We make crosses on our flowering agaves during the early summer, then in some cases, must wait until fall to see if we were successful. If we don’t get pods formed within a few weeks, we know that the particular cross was a failure, but in some cases, the cross forms pods, but there is nothing viable inside. This usually occurs when we make what’s known as a wide cross, using more distantly related species.
The stalk below is from a plant of Agave x ovatispina that flowered this year. Agave x ovatispina is itself a previous hybrid we made of Agave flexispina x Agave ovatifolia. We flowered our first clone of Agave x ovatispina last year, and it produced no viable seed, so we’re hoping for better luck with our second clone.
As you can see below, we had seed pods form.
When we opened the pods, we found that most of the seed (those colored tan) are not viable. Only a few black seed (potentially viable) were present.
The interesting thing we noticed was that viviparous (clonal) bulbils had formed on the top of the stalk. This trait occurs on a few agave species, including occasionally on Agave ovatifolia. While these plants are clonal, we often see variegation appear on these plantlets, so they’ve been planted as we wait to see what emerges.
In case you missed it, the USDA just issued their Updated Winter Hardiness Map, led by former PDN/JLBG staffer, Dr. Todd Rounsaville. While the results show an expected warming trend, the results are a bit concerning from the point of view of what plants people will be encouraged to plant. You can find the new map here.
The new map shows our location outside Raleigh, NC, as moving from Zone 7b to Zone 8a. Since the purpose of the map is to show people what they can grow in each zone, this is troubling. Using a 30 year data set, our winter low temperatures average out to 13.03 degrees F. That temperature is certainly Zone 8a, but when you look at the low temperatures experienced during that 30 year stretch, we experience six years where the temperatures were well below Zone 8a.
During that stretch, we have had:
4 Zone 9a winters, with a low of 20-25 F
7 Zone 8b winters, with a low of 15-20 F
13 Zone 8a winters, with a low of 10-15 F
3 Zone 7b winters, with a low of 5-10 F
2 Zone 7a winters, with a low of 0-5 F
1 Zone 6b winter, with a low of -5-0 F
Therefore on 6 occasions during the last 30 years, all of your Zone 8a plants would have died. Is this really acceptable? We think not.
Having been on the map committee in 2012, we requested that items like this and many other map deficiencies be addressed with the new map, which does not seem to have occurred. If the purpose of the map is simply to show how the low temperature averages have changed on average, then the map works fine, but it is actually used for so much more. I hope the USDA will come up with a plan to address these concerns.
This is the first time since 2010 our region has hosted the event, which moves throughout the Southeastern US each fall. This year, the sold out meeting welcomed 225 attendees, which included 56 International participants. The educational sessions were held at the RDU Airport Doubletree, and the bus tours ranged from Bahama in Durham County south to Johnston County.
Speakers covered a wide range of propagation/production topics, including our own Aaron Selby, who shared our “secrets” for propagating many of our rare and difficult to propagate crops. The student competition talks are always fascinating to see what research is in the academic pipeline.
The meetings always consist of both a live and silent plant auction, where all kinds of horticultural treasures abound. Below is Dr. Mike Dirr (retired UGA professor/author), and Dr. Todd Lasseigne (Director of Bellingrath Gardens), extoling the virtues of a plant in the live auction.
Our live auctioneer was non other than NC’s past Attorney General, Secretary of State, and famed Watergate lawyer, Rufus Edmiston. The 81 year old Edmiston is an ardent gardener, so he was right at home with the group. Below he is with gardening celebrity, Brie Arthur (l), Edmiston, JC Raulston Arboretum director Mark Weathington, and Plants Nouveau co-owner, Linda Guy (r).
Walking through the nursery this week, we spotted a fascinating triangle orbweaver spider (Verrucosa arenata). These cuties are usually seen in late summer and fall in open woodlands. Their diet focuses on small insects such as mosquitoes, but cause no harm to humans, except arachnophobes. We love the color echo with the ground fabric and pieces of bark.
I recently had the opportunity to visit the grape breeding trial garden of grape savant, Jeff Bloodworth of Orange County, NC. I didn’t realize it until my visit that Jeff, now 73, and I were in the Horticulture Department at NC State together from the mid to late 1970s. While I was starting on my undergraduate work, he was working on a Masters and later a Doctorate. After school, Jeff went on to become a Research technician with NC State grape breeder Dr. Bill Nesbitt, until he unexpectedly passed away in 1983 at the age of 51.
Departmental leaders decided to do away with the grape breeding program due to a lack of commercial interest in NC, so Jeff saw an opportunity. Scrambling quickly, he found and purchased 12 acres in rural Orange County, where all the NCSU research genetics found a new home. Jeff, and his wife, Peggy, still live on the same property today.
I’ve grown and studied muscadine grapes for almost 40 years, but Jeff’s little finger has far more knowledge than I dreamed existed. To say Jeff is obsessive about his work with grapes is a grand understatement.
We were joined by video producers Bill Hayes and Erin Upson of Carboro’s Thunder Mountain Media, who are working on a video project to help tell Jeff’s amazing story.
Until 2013, Jeff had never introduced a single new grape. Part of the reason is that his breeding goals were regarded as impossible “pie in the sky” ideas. Jeff was trying to cross seedless bunch grapes (pictured below), which grow well in California, but sulk in our summers, with the Southeast US native muscadine grapes.
After 10 years of no success, he finally was able to secure a viable offspring, and so was off to the races. Despite this eventual breakthrough, Jeff struggled to get any commercial or academic entities interested in his creations.
That was until plantsman and Gardens Alive owner, Niles Kinerk and his team, heard about Jeff’s work, and soon after, hired Jeff as an employee, providing some welcome financial support. Below are Jeff and Peggy Bloodworth with Mark Wessel, Gardens Alive Director of Horticultural Research.
Jeff’s first introduction through Gardens Alive, in 2013, was the light purple Vitis ‘Razmatazz’. This small-sized grape was the first seedless muscadine hybrid on the market. Although the fruit size is small by conventional standards, it is long producing as well as deliciously sweet. This was followed a few years later by Vitis ‘Oh My’, a bronze fleshed, larger seedless muscadine hybrid.
My trip last week was to join the Gardens Alive team as they sampled the new hybrids and made their final selections for future introduction. I was particularly excited by one of Jeff’s hybrids with 1″ seedless bronze grapes, but Jeff explained by slicing the grape in half and examining the ovary, that this was a female grape, which would need a male pollinator. Most commercial muscadine varieties are “perfect”, with both male and female flowers on the same plant. The size of Jeff’s seedless grapes continue to increase, and the variance of sweet flavors are astounding, so the future of grapes in the Southeast US is very exciting.
Nearby Jeff’s farm, investors have purchased much of the regional farmland with the goal of large scale production, including hundred of acres of Jeff’s grapes. We salute Jeff’s brilliance and persistence in this amazing endeavor!
Plant breeding is a wonderful hobby that attracts an array of hobbyists, as well a plant professionals. Many plants, such as hemerocallis, hosta, hibiscus, and iris, are so easy that they attract the majority of hobbyist breeders. Professionals and the craziest of the breeders occasionally focus on more difficult plants that few others are willing to try. This includes plants where the pollen exchange is complicated either by timing, incompatibility, or other constraints. Such is the case with century plants (agave).
Peak flowering season for 2023 is drawing to a close at JLBG, while one new agave is just in mid-spike. We only had 13 different agaves flower this year, compared to 18 last year. Fortunately, we are able to save and store pollen in the refrigerator, where it will remain viable for at least 5 years.
Below are a few images of Steve Guptill of our garden staff, as he made crosses last week. At the bottom of the first image is our volunteer agave specialist, Vince Schneider, who is training Steve to make the crosses.
With agaves, the process involves waiting for the stigma to become sticky–a sign that it’s receptive to the pollen. Pollen is then gathered from our prospective father and then hauled up the 21′ ladder to the waiting stigmas. Not only are you high in the air, but you’re working around hundreds of bees that are busy gathering copious amounts of nectar.
Assuming we get seed set, they should be ripe by late September/early October.
Both spiking agaves in the photo below are our selected hybrids from previous years breeding.
With what seems to be an endless array of Hydrangea paniculata cultivars entering the market, July has turned the garden into a snow white scene. The Asian Hydrangea paniculata was first published as a new species in 1829, but was not grown in the Americas until Arnold Arboretum director, Charles Sargent brought back seed from an 1892 expedition to Japan. That original plant, now, 131 years old, measures 16′ tall x 25′ wide. I’m not saying you need to plan for your Hydrangea paniculata to reach 131 years old, but the average of a house in the US is 46 years, so logic says we should at least plant for a 50 year mature size.
Below is our clump of Hydrangea ‘Rensun’, which is marketed under a completely different name, Strawberry Sundae. The introducers of this lovely clone tout this as maturing at 5′ tall x 4′ wide, but our 6 year old specimen is already 7′ tall x 11′ wide. Based on that growth rate and the mature size of the species, I’d expect it to reach 14′ wide x 22′ wide in 50 years. It’s truly fascinating why it’s so difficult to for plant breeders to get more accurate measurements before these plants are introduced to market. One can only imagine the maintenance problems caused when you locate plants based on the size given on the plant tag, only to have the plant get 2-4 times as large as your space allows.
JCRA’s Amorphophallus titanum ‘Wolfgang’ put on quite a show from June 20-23, and now it’s time for our ‘Homo Erectus’ to shine. We anticipate the blessed event at JLBG/Plant Delights beginning on Friday June 30, but please understand that trying to predict nature is anything but an exact science.
Below is an image from June 23, when our plant had reached 51.5″ in height. While most of the Amorphophallus titanums that flower, produce a creamy white spadix (the tall phallic thingy in the center), ours is the much rarer purple spadix form–no doubt due to greatly increase blood flow.
This link takes you both to our live stream, some history, titanium trivia, and any updated hours that you can come say hello to ‘Homo Erectus’ in person. Current visitation schedule: Monday – Thursday, 8:00am – 5:00pm, Friday, June 30, 8:00am – 7:00pm, Saturday and Sunday, July 1 and 2, 10:00am – 7:00pm.
Those who were heavily into gardening in the early 1990s probably remember the micro-mail order nursery, The Wildwood Flower, run by the unique and colorful NC plantsman Thurman Maness. While Thurman’s nursery lasted less than a decade in the mail order realm, his impact in the horticultural world continues though his many plant introductions.
Thurman’s probably best known in the plant world for his lobelia hybrids, as demonstrated by his 1990 catalog which listed 20 different lobelias. We’ve offered a number of Thurman’s lobelia hybrids through the years, including varieties like ‘Rose Beacon’, ‘Ruby Slippers’, and ‘Sparkle deVine’, and still carry one of our personal favorites, Lobelia ‘Monet Moment’.
Thurman’s old catalogs also included little known, but garden worthy natives like Scutellaris serrata and the Federally Endangered Silene catesbiae (polypetala). When I first visited back in the early 1990s, Thurman was running his own tissue culture lab, where he was both producing plants as well as conducting ploidy manipulation for breeding..
So, what’s Thurman doing today. At age 87, he’s still working in his garden and propagating plants, which he occasionally sells on site at his Pittsboro home. He tells me that he’s ramping up production because of the new 400 acre development just a few miles away…he’s determined that they all need hydrangeas.
He also still runs his antique business, now from an antique mall in nearby Siler City. When he goes out on the town, he often does so as his alter ego, Sparkle deVine, as you can see in this recent photo below. JLBG/PDN salutes a brilliant plantsman for a horticultural life well-lived.
The past couple of weeks the small, freakish flowers of one of the strangest of plants have begun to open in our gardens – pipevines. It’s difficult to believe that nature could summon up anything as strange as the flowers of pipevines. If you remember the “regular” aka actinomorphic and the “irregular” zygomorphic flowers from high school biology then you would have to consider the strange, inflated flowers of pipevines highly irregular.
These plants are related to wild gingers/heartleafs (Asarum) and are members of the basal angiosperms, which are plants with lineages that predate monocots and true dicots. Many of the early angiosperms have flowers that are pollinated by flies or beetles that they lure to the flowers with the pleasant smell of rotting meat or dung. Pipevine is no exception. They trick flies into entering the strangely shaped flowers which often have a funnel-like flare with a narrow opening and trap the fly in a chamber with the pollen and nectar to accomplish pollination.
The general shape of the pipevine flower also approximates the anatomy of a uterus and birth canal. As was all the craze in the early years of medicine, the resemblance to the uterus must mean it is good for treating issues with difficult pregnancies and childbirth. This archaic mode of determining herbal remedies is referred to as the doctrine of signatures – basically if a plant part looked like a part of the human anatomy it would be used to treat ailments associated with that organ. This avenue of medical care led us to the highly unsuccessful use of liverleaf (Hepatica) to treat ailments thought to be caused by the liver, like cowardice and freckles. Medical science has since progressed, maybe?
The pipevines include herbaceous upright perennials, short rambling vines, and enormous lianas (woody vines). The toxic chemical aristolochic acid is contained in all parts of the plant and though it is known to cause kidney failure (which probably didn’t decrease the problems with difficult childbirth) this chemical has also been shown to have antitumor properties. Don’t go munching on the leaves! Pipevine Swallowtails depend exclusively on pipevines for their larval food source and all the species we grow are host to large numbers of caterpillars in the summer.
The Pipevine Swallowtail accumulates aristolochic acid which deters predators like birds from wanting to consume them (they don’t want kidney failure either). This may explain why Spicebush Swallowtails and Red-spotted Purples look so similar to the Pipevine Swallowtail, they’re taking advantage of blending into the poisonous crowd.
These beautiful butterflies always seem to find your pipevines, no matter how secluded you think they are. Don’t worry, we can’t have enough swallowtails and the vines regrow without issue. These are great plants to include in your garden to support our butterflies. The caterpillars have another interesting behavior, when disturbed they have bright orange “horns” that are technically referred to as osmeteria that it pushes out of the front of its body and emit a very foul odor!
Three native pipevines are found in the Carolinas. Common Pipevine (Isotrema macrophyllum) can become a huge liana, reaching the canopies of old-growth trees and spreads through runners and can be difficult to keep contained. It grows best in cool climates and tends to suffer or not grow in warmer parts of the Southeastern US.
Woolly Pipevine (Isotrema tomentosa) grows very well in hot, humid climates and is known from only a few native populations in the Carolina coastal plain. Like its mountain cousin it is very difficult to restrain and may quickly outgrow the space you envision for it.
The only other pipevine is very dissimilar to the others, Virginia Snakeroot (Endodeca serpentaria), which is an upright herbaceous perennial that rarely gets a foot tall. If you’re wondering why these former Aristolochia are now in the genera of Isotrema and Endodeca, well, it appears to all be about genetics. They are closely related but currently in different genera.
One of the easiest to grow and showiest, best-behaved species in our garden hails from Brazil, Argentina and Bolivia, Fringed Pipevine or Fringed Dutchman’s-pipe (Aristolochia fimbriata). The plants form scrambling vines that act more like a groundcover than a vine and have beautifully silver-veined small leaves. The flowers are intricately patterned with lines and fringed with long “tentacles” to create one of the most bizarre flowers you’ll ever include in the landscape. Though you wouldn’t pick a plant from Brazil to be rock-hardy here in Raleigh, this one has been fully hardy (zones 7a-9a). For those of you looking to add some swallowtails but unwilling to devote the space to a monstrous mass of vines this one is for you. Fringed Pipevine is also incredibly drought-tolerant and perfect for part-sun to dappled dry shade.
For those who regularly attend our Open Nursery and Garden days, you have no doubt watched the evolution of our new dryland rock garden by our welcome tent. I thought it would be fun to look back at its short evolution. Below is Jeremy’s bed outline from late January 2021, when this new bed was only a vision in our heads.
In late January 2021, Jeremy broke ground by digging down until we reached undisturbed subsoil, which was then loosened.
The next step was to add our planting mix, which consists of 25% native soil, 25% compost, and 50% Permatill (a popped slate gravel). The planting media was thoroughly mixed with the subsoil, which ensures continuous drainage by not layering different soil types. The final height of our bed was 5.5′, with the knowledge that we would loose about 6″ in final height to settling. Planting began in early March 2021.
Below is the same area taken this week–27 months after construction. The bed is 35′ long with an average width of 15′, which would give us 525 square feet of bed space–if the bed was flat. With our finished height of 5′, we actually have close to 800 square feet of planting space–50% more surface area, all because we raised the bed height.
Because these are dryland plants, this section of the garden is un-irrigated, except during extended periods of severe drought and above normal heat. We hope this “peaks” your interest in both the science and art of rock gardening. If so, the North American Rock Garden Society (NARGS.org) is an amazing group of like-minded folks with an incredible seed list of treasures for this type of garden.
Here’s an early June shot from the garden. The conifer in front left is Picea abies ‘Glauca Pendula Oxtail’. The weeping conifer in the distance is Cupressus glabra ‘Raywood’s Weeping’. The bright shrub in the distance is Ligustrum lucidum ‘Marble Magic’. Delve more into the world of woody ornamentals during the upcoming Southeastern Plant Symposium and Rare Plant Auction, June 16-17, 2023, hosted by JLBG and JCRA. Register now for in person or online attendance.
This spring, we flowered the highly confused NC native wild ginger, mistakenly known as Asarum memmingeri in the garden. In reality, it’s never been given a proper name, so we refer to it as Asarum sp. nov. Allegheny Wild Ginger. Below, Patrick explains how this ginger was dropped into a botanical abyss, and what needs to be done to return it to proper recognition, and to correct a cascade of past taxonomic errors. -ta
When I was a boy the tiny-flowered evergreen wild gingers that grew all over our land in Alleghany County, North Carolina seemed like they must be a common species, and should have a name. As a boy of 12, however, I had a hard time placing a name on them since they didn’t seem to fit the photographs in popular wildflower books or match the plants that my grandmother’s flora called Hexastylis virgnica (now Asarum virginicum).
I became obsessed with heartleafs as a child and the curiosity remains strong. When I entered college I was lucky enough to take Dr. Peet’s Ecological Plant Geography class at the University of North Carolina, Chapel Hill. Our class, which was all graduate students and me (as a sophomore), was expected to do a project detailing and explaining the range of a particular genus or family of plants. I chose the smooth-leaved evergreen Asarum, then known then as Hexastylis.
I spent the spring semester travelling to every corner of the American South seeking species I didn’t know and trying to fill in the vacant counties in the range maps of those species that I did know. I took countless measurements of calyces and made copious notes on habitat. I was shocked when I travelled to southeastern Virginia to visit the area where Asarum virginicum was likely first collected. These true Asarum virginicum plants were nothing like the “A. virginicum” I was so used to seeing in my boyhood home.
A quick trip to the Earl Core Herbarium at West Virginia University, and later to the Smithsonian, brought to light a serious problem with what botanical taxonomists currently refer to as Asarum virginicum and an even larger problem with what we call Asarum (Hexastylis) rhombiformis and Asarum (Hexastylis) memmingeri.
It seemed as if the Alleghany County plants I had called Asarum virginicum as a child had been mistakenly identified by WVU taxonomist Earl Core as Asarum memmingeri. Complicating this further was that the probable original type specimen for A. memmingeri would later be published under a new name, H. rhombiformis!
To make sense of the cascade of errors, we need to go back further in time. This story begins in 1897 with W.W. Ashe’s publication of The glabrous-leaved species of Asarum of the southern United States in the Journal of the Elisha Mitchell Scientific Society. Here, Ashe describes for the first time Memminger’s Heartleaf (A. memmingeri). From the description it is obvious that he is describing a plant with a very small flower with a very narrow opening (7 mm wide or less).
Error #1 occurred when Ashe described the original type locality as Mitchell County, based on a collection by E.R. Memminger. When I was looking for a type specimen, the best option I could find was a specimen collected (in duplicate) by E.R. Memminger himself that he says in his own handwriting represents the type location. During Ashe’s time, it was not required to designate a type specimen, but the problem was that Ashe’s citation of Memminger’s specimen was actually from Henderson County (“Tranquility”, Flat Rock, NC), not Mitchell County.
Type specimen of Asarum memmingeri collected by E.R. Memminger
Error #2 occurred as we fast-forward to 1987, ninety years after Ashe published his work, when L.L. Gaddy described a new species of Hexastylis that occurs in Southwestern NC and Northwestern SC asH. rhombiformis (Asarum rhombiformis (combination not yet made). In this description he cites E.R. Memminger’s specimen from Henderson County, which, is actually the type specimen of Asarum memmingeri as representing his new species H. rhombiformis. Consequently, the name H. rhombiformis is invalid and this plant should be known as A. memmingeri.
Error #3 occurred when J.K. Small of the New York Botanical Garden, Earl Core of West Virginia University and others annotated (attributed) numerous Asarum collections from West Virginia, Virginia, and NC, of an un-named species that they mistakenly identified as A. memmingeri. Blomquist and all modern authors have since combined these tiny-flowered plants with small openings to the calyx tube within a “catch-all” concept of A. virginicum. Other taxonomists since have followed their mistaken identification of A. memmingeri or A. virginicum for these plants that are known to range from WV south to NC.
We know that these plants that J.K. Small, Earl Core, and others called A. memmingeri actually represent the heartleaf from my Alleghany County childhood homestead and surrounding regions that still has no accepted name.
It is time to clear up the confusion and formally describe these plants along with a new, correct scientific name. For our purposes we will refer to them here as Allegheny heartleaf for a common name (in reference to the mountains, which have a different spelling than the NC county, rather than Alleghany County, NC).
In vegetative form, the Allegheny heartleaf is similar to most of its relatives including A. virginicum, minus, heterophylla, and naniflora. They are tightly clumping with leaves that tend to be as wide or wider than long with a broad cordate base. Though I have found populations with some mottling on the leaves, they tend to lack any variegation altogether.
The flowers on the undescribed Alleghany County heartleaf are much smaller in all dimensions and also differ in the tube constriction from both A. virginicum and true A. memmingeri.
The Allegheny heartleaf is found in typical heartleaf habitat: highly acidic, organic duff beneath oaks and pines and often in association with Rhododendron and Kalmia. They are found along the margins of Southern Appalachian fens and small stream swamps as well as along stream banks and on steep rocky slopes and bluffs that are most often north or east-facing.
The natural range of the species seems to be from Watauga/Avery counties North Carolina, north through West Virginia at low to moderate elevations. In North Carolina nearly all populations are located along the New River drainage, though there are outliers along the Yadkin River drainage downstream to Donaha Bluffs in Forsyth County. This taxa is tightly tied to the Appalachian range with outliers into the piedmont in areas with cool microclimates along rivers that originate in the mountains. Between the mountain populations of Allegheny Heartleaf and the coastal Virginia Heartleaf (Asarum virginicum) occurs A. minus, which largely replaces Allegheny Heartleaf in most of the piedmont of North Carolina.
Allegheny Heartleaf was very difficult for me to grow, even in seemingly hospitable microclimates in Clemson, South Carolina. It seemed to survive but only for a short time, gradually declining and producing dwarfed leaves by the 2nd season and then disappearing by the 3rd. I am extremely pleased to have this species growing strong, flowering and producing normal sized leaves for its second season here at Juniper Level Botanic Gardens.
What needs to happen is for Hexastylis rhombiformis to have a name correction to Asarum memmingeri, and for the plant widely known as Asarum memmingeri to finally be named for the first time, hopefully with a specific epithet named for the Allegheny Mountains, which incorporate the heart of its range.
Since we opened the Souto sun garden section of JLBG to the public, circa 2014, we’ve been dealing, rather poorly, with an unsightly water runoff capture pit on the east side of the garden. The 30′ x 30′ pit was first filled with weeds, and later converted to a bed for marginal aquatics like cannas and crinums. Over the last few years, cattails had taken over, rendering it somewhat more attractive, but far less diverse.
Three years ago, we made the decision to transform it into a styillized bog garden/rock garden combination. To do so, would require the elimination of the cat tails, which took the better part of two years. Last year, with the cat tails finally eliminated, Patrick, Jeremy, and I strategized what we wanted the bog to look like and how we would make it happen. Armed with everyones’ input, Jeremy took over the construction design and implementation.
Our first step was to remove several truckloads of squishy muck that covered the bottom, since this would not provide the stability we needed to set large rocks.
With the pit finally firm and level, it was time to closely examine water flow from both surface and subsurface water.
Next, the pit was re-filled with our native sandy loam, with a central “gravel burrito”, which would allow subsurface water a way to exit without erupting upward into the planting area.
The next step was the installation of underlayment and the pond liner. Despite the site being already waterlogged due to a high water table in the area, we felt that the use of a liner would give us more precise control over the water level.
To keep the liner from floating while we worked, we began refilling the bog with our new soil mix of 50% native sandy loam and 50% peat moss. Around the edges, where the rock garden would be installed, we used a base of concrete blocks to support the weight of the rocks. These were located on the outside of the liner, so the blocks would not leach chemicals into the acidic, nutrient deficient bog.
In the center of the bog, we used double-wall drain pipe, stood on end to support the centerpiece of huge boulders.
The large rock feature was then installed on top of the support pipes, along with an ancient stump which Jeremy unearthed on the property.
Rocks with planting pockets were then installed along the edge on top of the cinder block wall. .
The final step was the installation of entrance steps into the bog and pathway stones, which will allow visitor a closeup view of the plants. Initial plants are in the ground, but more will be added as they are ready. The crevices planting mix (same as the bog) has a pH of around 4.0, compared to all our other crevice gardens on the property, which have a pH around 8.0. This should allow us to grow an entirely new array of plants.
From start to finish, the entire project took Jeremy, Nathan, and some occasional help from other staff, 3 1/2 weeks…job well done!
We hope you’ll drop by during our spring open house and check out the new Rock Bog in person.
We were delighted to have the amazing UK botanists, John and Soejatmi Dransfield drop by this week for a visit. Both are retired scientists from Kew Garden, where Dr. Soejatmi Dransfield specialized in paleotropical bamboos, and Dr. John Dransfield specialized in palms. It turns out that John also works with podophyllum in his retirement, so we had a blast chatting about our mutual work with the genus as we wandered the garden. Both are incredibly keen plant lovers, so we hope for another visit when we’ll have even more time to wander and talk plants!
Despite the impending flooding late last week, Patrick, Zac, and I took off to the mountains of western South Carolina for a few days of botanizing. Despite the monsoon-like rains, we managed to visit seven amazing sites. Below is a highlight.
One stop was at a giant granitic outcrop. The rocks are covered in an array of mosses, lichens, and other associated flora, most growing in shallow pockets or organic debris that alternation from inundated to bone dry for months.
Large patches are covered with the colorful, 1″ tall, annual sedum, Diamorpha smallii, commonly known as Elf orpine.
Another site also had large granite flatrocks, but with a complete different flora. Here, two dryland ferns, Cheilanthes lanosa and Cheilanthes tomentosa formed large patches, along with the amazing Selaginella tortipila.
The more shaded slopes were filled with amazing clones of the dwarf painted buckeye, Aesculus sylvatica, which at this site, mature at only 3-5′ in height. In most other area, the same species matures at 10-20′ tall. The flower colors here ranged from peachy yellow to screaming orange red.
One of our next stops was an amazing watershed where, Shortia galacifolia grows by the acre, carpeting the mountain side. This is the world’s largest population of this amazing native. We even found it growing epiphytically on a rock, perched in the middle of a stream.
The native Micranthes micranthidifolia grew along the moist stream banks. This is the first time I’ve seen this, since I first purchased the plant back in 1995 from the former We-Du Nursery. In that case, I killed it, before getting it planted.
Another plant I’ve killed in my previous attempt was the native climbing fern, Lygodium palmatum. Here, it grew with the easy-to-grow Christmas fern, Polystichum acrostichoides.
The difficult to grow Asarum heterophyllum was scattered throughout our several mile trek, almost all plants were the solid green leaf form.
Far easier to grow is the native Hydrangea radiata (formerly known as H. arborescens var. radiata), with its shimmering white-backed leaves.
As we walked along the towering cliffs, the red fruit adorning the carpets of partridge berry, Mitchella repens glistened in the rain.
Several patches of mayapple, Podophyllum peltatum had some of the largest foliage that I’d ever seen, measuring 1′ in width.
Not far away we saw some of the most strikingly patterned form of Pachysandra procumbens we’ve ever seen.
We almost got through the entire trip without finding a single variegated or colored foliage mutant, when not far from the parking area, we spotted a streak sport on Kalmia latifolia.
Below is our incredible, but soaking wet, botanizing team (l-r) Adam Black, Bartlett Arboretum, Zac Hill, JLBG, Patrick McMillan, JLBG.
We continue to be impressed with the continuing parade of new selections of sterile lenten roses, in particular, the clones of Helleborus x iburgensis. These fascinating hybrids that originated at RD plants in England, are crosses of Helleborus x ballardiae (niger x lividus) x Helleborus x hybridus. In other words, these hybrids have up to 5-7 different species in each.
Because two of the parents, Helleborus niger and Helleborus lividus, both have outfacing flowers, the flowers on the Iburgensis hybrids all carry that trait. Additionally, most every lenten rose cross with Helleborus niger is effectively sterile. Interestingly, Helleborus niger is the most cold hardy of all lenten rose species, while Helleborus lividus is the least cold hardy, but the most heat tolerant.
Below are a series of photos from the gardens here over the last few weeks of some of the clones we have tried. We find these an exceptional group, many with pink to cream variegation, that should be much more widely grown. Hardiness is Zone 5a-8b, at least.
The horticultural world just lost another stalwart with the passing of plantswoman, Sally Walker, 87, of Southwestern Native Seed. After departing her native England, by way of New Zealand, and later California, Sally and her husband Tim, settled in Arizona in the 1960s. After working for several renown nurseries in both the UK and US, she started her own seed company, based out of Tucson in 1975, which would become Southwestern Native Seed.
Over the next 32 years, Sally was one of the only sources of many southwestern native plants, introducing several great new plants to commerce including Agastache rupestris, Penstemon cardinalis, and Aquilegia desertorum. Her relentless travel schedule took her throughout the Southwestern US and into the mountains of Northern Mexico first to find and study the plants and then return a second time for seed.
I would always drop what I was doing when Sally’s catalog, filled with her own plant sketches, arrived.
We were fortunate to have Sally visit JLBG several times, and below is an image from her 2009 trip.
We’ve been fascinated with the woody plant genus Loropetalum since the late J.C. Raulston first distributed the pink-flowered forms, which had just come into to cultivation in the US, back in 1989. Since those original plants were propagated and sold, many nurseries have tried to one up each other with a barrage of new introductions. Today, we have documented 68 named cultivars of Loropetalum, of which we currently grow only 22. Below are a few from JLBG, which are currently in full flower.
Sadly, most folks mistakenly think these are foundation shrubs, thanks to unscrupulous retailers. Most, are in fact, either large shrubs or small trees. Yes, if you’re into plant mutilation as a form of legal S&M, you can shear them into bizarre boxes and meatballs, but do you really think this is a good idea? Do you really hate natural beauty that much?
Below are a few named selections with their advertised sizes and their actual sizes, so you can plant them in the proper place. Winter hardiness is Zone 7b-9b.
Loropetalum ‘Snow Panda’ has been truly outstanding for us. It was introduces as maturing at 10′ tall x 9′ wide, and our 7-year-old plant is now 7′ tall x 12′ wide.
Loropetalum ‘Zhouzhou‘ is sold as ‘Zhoushou Fuchsia‘ and as ‘Pipa’s Red’. These are listed as maturing at 5′ tall x 6′ wide and 12′ tall x 12′ wide, depending on which name is on the tag. The reality is that it matures at 30′ tall x 20′ wide, as you can see below with our 27-year -old specimen.
Loropetalum ‘Ruby Snow’ is a fascinating chimeral misfit (think schizophrenic) selection with both white and pink flowers. The introducer touts it as maturing at 6′ tall x 6′ wide, but our 6-year-old specimen is already 8′ tall x 14′ wide, so this will get far larger than the tags indicate.
Loropetalum ‘Daruma‘ is an extremely heavy flowering selection that is sold as maturing at 5′ tall x 5′ wide, but this isn’t even close. The 6-year-old specimen below is already 6′ tall x 9′ wide, and our oldest specimen had to be removed from its original location after it reached 16′ tall x 16’ wide.
Loropetalum ‘Shang Hi’, sold under the marketing name Purple Diamond, is touted as maturing at 5′ tall x 5′ wide. Ooops–our 14-year-old plant is already 15′ tall x 15′ wide. Perhaps we need to give remedial measuring courses to some of our nursery folks.
Loropetalum ‘GrifCRL‘, marketed as Little Rose Dawn, is incredible in flower, but it’s marketed as maturing at 10′ tall x 10′ wide, and our 16-year-old specimen is now 18′ tall x 18’ wide.
Loropetalum ‘Crimson Fire’ is much more red than most selections. The introducer claims it will mature at 4′ tall x 5′ wide, but our 6-year-old plants are already 10′ tall x 10′ wide.
These are just a few of the amazing selections, but keep in mind to never trust plant tags when it comes to where you should plant your plants to keep from needing to butcher them.. Until nurseries and plant introducers learn to care more about the end consumer’s success, it’s always a good idea to visit botanic gardens and determine the true size for yourself.
This winter, we were mulling over options for our a bed along the walkway to our nursery and garden office. We had previously had a narrow raised bed, but this was backing up rain water on our sidewalk. The garden and research staff proposed that we remove the raised bed and install a bog garden/rain garden to catch and use the runoff from the office roof.
The first step was removing the existing plantings, followed by an excavation to 2′ in depth, being sure the bottom was level.
An overflow pipe was installed at the east end at a level where water would never pond in the top few inches.
The next step was the addition of a pond liner, followed by several inches of washed stone gravel. Just covered by the gravel was a horizontal pvc pipe, connected to a vertical tube, which would provide a way to add water from the bottom up, should such ever be needed.
On top of the gravel, we added about 15″ of a soil mix, comprised of 50% native sandy loam from the property and 50% peat moss. Once the mix was thoroughly moistened, plantings began. We’ll continue to add small bog plants as the season goes, but we’ve already been through several significant rains, and the system functions beautifully. Water management is such an important factor in gardens, so we hope this gives folks an idea of how to turn a garden concern into a special plant habitat.
We’ve grown the native loblolly bay, Gordonia lasianthus for several decades, but I’d never stumbled on one as large as the one we spotted last week while botanizing in coastal southeastern North Carolina.
The specimen we ran across has a 26″ diameter and a height of 70′, which although huge, turned out to be slightly smaller than the state champions in Currituck County, which top out at 85-90′ tall. Posing by the trunk is the landowner, Vince and his son Vinny, who moved to coastal Carolina from Brooklyn, NY.
Also, on the same site, we found a population of Chamaedaphne calyculata, a bog-loving, blueberry relative with a circumboreal distribution in mostly cold and sub-arctic regions. When we returned, Patrick told me that it was quite rare in NC, but he found a singole documented record for North Carolina on Hwy 211 in Brunswick County (Vince’s property), that we’d accidentally stumbled upon. Sadly, Hwy 211 is being widened, so this population, along with many other amazing natives are in jeopardy. Fortunately, we now have a small division now growing in our ex-situ conservation garden at JLBG.
Platycladus orientalis ‘Van Hoey Smith’ is looking absolutely fabulous in our garden this winter. This fascinating selection of Oriental arborvitae, Platycladus orientalis was named after the late Dutch conifer guru, Dick van Hoey Smith (1921-2010), by an American nurseryman, who reportedly received these cuttings, unlabeled, from Dick. Some conifer folks think this is actually an old cultivar, Platycladus orientalis ‘Aureovariegata’. I understand this is not a good performer in climates with low humidity, but it sure likes it here in NC. Winter hardiness is Zone 5b-9b.
So, who is Van Hoey Smith? Born, James Richard Pennington van Hoey Smith, Dick’s family started the famed Trompenberg Arboretum in Holland, which Dick later ran from 1950 until he handed over the reins to his successor Gert Fortgens, in 1996. If you haven’t visited, I highly recommend a visit for any keen plant lover.
I had to chuckle as folks on several Facebook plant groups were wringing their hands in worry prior to the recent cold snap, while we were secretly hoping for even colder temperatures than forecast.
JLBG registered three consecutive nights in the teens recently; 11F, 19F, and 19F. While this was certainly not abnormal for our area, folks with very short memories thought the horticultural world was coming to an end. In reality, we recorded similar temperatures in the winter of 2017/2018, albeit a week later that year.
When we first started the gardens at JLBG, we were squarely on the Zone 7b side of the Zone 7a line. We are now on the Zone 7b side of the Zone 8a line. In order words, we have shifted about 1/4 of a hardiness zone. Since 2018, JLBG has registered three consecutive Zone 9a winters, so it’s not surprising the new gardeners or those with short memories start assuming that all kind of plants are reliably winter hardy, which is not the case.
We long for cold temperatures because we want and need good winter hardiness data, and while mild winters may be enjoyable to us Homo sapiens, we don’t learn anything about plant hardiness from those winters. So, here are a few things we learned this year.
Agave weberi ‘Stone Cold Austin’ is Patrick McMillan’s collection of Agave weberi from Austin, Texas. We’ve tried Agave weberi a couple of times prior, and could never get it through one of our milder winters. Patrick’s original plant at Clemson got large enough to flower there, so we’re hoping for the same. The older foliage is showing damage from 11F, and will most likely be lost, but the bud seems fine so far.
We’ve never had any luck with any of the dwarf Agave lechuguilla mutants we’ve tried in the garden, but this new one, shared by plantsman Hans Hansen, that we call Agave ‘Tater Tot’, had no problem with 11F. These are often sold as Agave x pumila, which actually doesn’t exist. Everyone assumed that A. x pumila was a hybrid, but when one in Europe recently mutated back to the original form, it turned out to be nothing more that a super dwarf form of Agave lechugullla.
Mangave ‘Racing Stripes’ is a plant we had high hopes for in terms of winter hardiness, but we had not had a cold enough winter to get good data. Our only reservation was that it contains genes from the tropical Agave gypsophila. Thankfully, our plant came through the 11F freeze in reasonably good shape. The wrinkled nature of the older leaves are indications of cold damage that will show up in a few more days, but the core seems intact and should re-grow.
We fully expected Bambusa multiplex ‘Green Giant’ to be defoliated after 11F and the stalks killed to the ground, but our fully exposed clump still looks like it’s mid-summer…at least from the north side.
On the south side, the same clump has fried foliage. There are typically two causes for such damage. One is wind desication when the winds are blowing from a single direction and the ground is frozen, making it impossible for the plant to replenish water lost through the foliage. During the time that our ground was frozen, our winds were coming from the West, so that wouldn’t account for damage only on the south side of the plant.
In this case, the more likely scenario is that this is due to sun scorch when the soils was frozen, since the damage is on the south side. If the canes are indeed undamaged, as it appears, new leaves should reflush in spring.
We didn’t hold out much hope for the Mexican palm, Brahea decumbens, but it sailed through 11F unscathed.
Since we know that genetics matters, we will often plant more than one clone of a marginal plant like a new palm. Below are two seedlings of the small-seeded European Fan Palm, Chamaerops humilis var. microcarpa. The first shows significant foliage burn, while the second plant, growing nearby shows no damage after 11F.
The hardiest of all Sabal palmetto forms are those from NC’s Bald Head Island. Our plant from there came through the cold unscathed. We expect many local businesses and even homeowners who purchase large trunked forms directly from Florida growers will probably be in for a disappointing spring.
All of our hardy cycads have assumed the straw-color we see every year when the temperatures drop below 18 degrees F. The plants are fine, but we recommend waiting to remove the dead fronds, since doing so now, can cause the new foliage to emerge in the middle of winter, which is never a good idea. April 1 is our target date to remove the fried foliage.
One of the real surprises was the fried foliage of Viburnum ‘Moonlit Lace’, where it was growing in full sun. The same plant growing in shade looks untouched. The stems are fine and the plant should re-sprout fine, but gardeners who grow this in full sun may be disappointed.
This is the coldest temperatures we’ve seen since planting Patrick’s hardy selection, Opuntia microdasys ‘Dripping Springs’. Our clump looks great after the cold. It’s hard to imagine that this clone is so much more winter hardy than any of the other forms of this species that we’ve tried previously and killed at much warmer temperatures. Although we don’t offer this for sales, I’ll remind you of our great prickly pear cactus giveaway at our Summer Open Nursery and Garden in July.
The Mexican Sedum praeltum looks a bit sad, but actually seems to be fine with sound buds up and down the stem. This little-known perennial forms a plant that looks almost exactly like the tender Jade plant, Crassula ovata.
Lastly, our patches of Living Stones, Lithops aucampiae, sailed through 11 degrees F. I wonder if we can ever get all the disinformation on the Internet regarding their tolerance to cold corrected.
We’ve long been enamored with the Southwest native genus of slow-growing woody lilies belonging to the genus, Dasylirion. Since the early 1990s, we’ve been growing these, trialing as many species as we could obtain to see how well they adapted to our climate here in the colder, wetter Southeast.
So, far, we have grown 16 of the 21 recognized species and succeeded with 12. We found four unable to survive our coldest winters, including Dasylirion durangensis, Dasylirion longissimum, Dasylirion lucidum, Dasylirion sereke.
The five species we have yet to try in the garden are Dasylirion graminifolium, Dasylirion longistylum, Dasylirion micropterum, Dasylirion palaciosii, and Dasylirion simplex. We have seed planted of both Dasylirion graminfolium and micropterum, so those will be next in line for our in ground trials. That leaves us still searching for seed of the final three.
Sotols, like agaves, are members of the Asparagus family. They are becoming wildly popular, but not because of gardeners. Instead, their popularity is driven by those who are driven by a need/desire to imbibe alcoholic spirits. First, there was Mescal, a Mexican drink made from one of a number of different agave species, depending on what grew in proximity to each village. Of the Mescals, the most popular is Tequilla, which is made from a single species, Agave tequiliana.
Now, Sotol alcohol has joined the ranks of the “hot new spirits”. Made from agave’s cousin, plants of the genus Dasylirion, Sotol is rapidly becoming the new “flavor of the month”. Sotol alcohol certainly isn’t new, and if you regularly travel south of “the wall” you probably already know that Sotol is the state drink of Mexican states Chihuahua, Coahuila, and Durango.
Not so long ago, Sotol alcohol had a history that somewhat parallels moonshine in the Southeast US. For years, Sotol alcohol was illegal and subject to government raids, during which master sotoleros were punished or imprisoned. During the US prohibition of the 1920s, Sotol sales in the US skyrocketed, but soon after its repeal, Sotol sales plummeted back into obscurity. Now, with not only social acceptance, but a wide wide embrace of virtually anything that can be used to produce alcohol, Sotol has been mainstreamed with the assistance of the Mexican government and willing marketers.
Most agaves for Tequila production are now commercially grown in massive farms, and most plants are now produced from tissue culture for a more consistent yield and to take pressure off wild popuations. Even under ideal farming conditions, it take 5-7 years to get an agave large enough to harvest for tequilla production. With dasylirions, the same process takes at least 12-15 years according to Sotol marketers. Based on our 30 years of work with the genus, I’d say the time involved is more likely 24-30 years, even in a high rainfall climate like ours.
I’m not aware of many farm operations that can afford to grow a plant for that long before expecting a return on investment. This means that poaching of plants from the wild is very likely to increase. With such a low rate of return, i.e. 1 pint of liquor for each plant harvested, I can’t see the plants coming out on the good end of this industry. While making alcohol from dasylirions isn’t new, it’s been done on a very limited scale in Mexico, prior to word spreading around the world via social media.
Reportedly Sotol spirits taste quite different based on the species used, and whether it’s from an exceptionally dry region or an area with better rainfall. Sotol conniseurs describe the tastes as being a bit like menthol or pine/mushrooms if the plants are grown well hydrated, while those from drier regions taste more like leather. To quote Dave Barry, “I’m not making this up!” And this sounds appealing to who???
Supposedly, the spirit producers are cutting off the wild dasylirions and leaving the bases to resprout, but I’ve got my doubts about how well that works. Assuming the cut dasylirion does resprout, there will be a decade of lost seed production, so plant populations in the wild are almost certain to decline. I’m left to wonder if we really are so desperate for a new taste in alcohol that we are willing to sacrifice another genus of plants in the process.
In celebration of these amazing plants, here are photos of those we have grown in our ex-situ conservation gardens at JLBG.
Dasylirion acrotrichum, named in 1843, is native to Mexico’s Chihuahuan desert. Of the seven plants we planted, only one survived, which is now over 20 years old. This widespread sotol, which occurs on igneous soils, has been split by various authors into several subspecies. Undoubtedly, winter hardiness varies based on the seed procurement location. At maturity, the trunks can reach 5′ tall.
Dasylirion berlandieri, named after French/Mexican naturalist, Jean-Louis Berlandier (1803-1851), was first published in 1879. Native to steep rocky hillsides in Tamaulipas and Nuevo Leon in Northeastern Mexico, it’s one of the largest species in the genus in width, but with a trunk that never exceeds 1′ in height. Below is our plant in bud. Unlike agaves, dasylirion rosettes do not die after flowering.
Below is a fully open flower spike, which is abuzz with a large number of bees
Dasylirion cedrosanum, first documented in 1911, hails from 3,000′ – 6,000′ elevation on rocky, gypsum-laced hillsides in the Sierra Madre Occidental mountain range. They are restricted to the Mexican states of Chihuhua, Coahuilla, and Durango. At maturity, they produce a 3′ tall trunk.
Dasylirion durangensis is another species first described in 1911, which hails from the dry alkaline/limestone-gypsum deserts of Coahuila, Chihuahua, Durango, and Zacatecas. In parts of its range, it interbreeds with Dasylirion wheeleri. We flowered this prior to losing it during a particularly cold winter. Below is our Obit photo.
Dasylirion gentry was only published as a species in 1998. It has a very limited range between 3,500′ – 4,000′ in Sonora, Mexico, where it grows on rocky slopes in openings of pine/oak woodlands.
The inflorescense of Dasylirion gentryi is one of the most spectacular we’ve ever seen.
Dasylirion glaucophyllum is a species whose discovery dates back to 1858. It can be found naturally, only in Sonora, Mexico, growing on rocky hillsides at elevations to almost 8,000′. At maturity, trunks measure up to 6′ in height.
Dasylirion leiophyllum, published in 1911, only grows north of Mexican border in Texas and New Mexico. Based on where it grows, it should be one of the most winter hardy sotol species. The first photo is at JLBG, and the second in situ at 5,400′ elevation. The second image is from the late plantsman, David Salman, of a Zone 5 population he discovered and shared seed with us just prior to his untimely death. Plant Delights is currently offering this as Dasylirion leiophyllum ‘Chaves’.
Dasylirion miquihuanense, only described in 1998, hails from Tamaulipas and Nuevo Leon in Northeastern Mexico. Also occurring on rocky slopes, this sotol is one of the tallest species, producing massive 8′ tall trunks. We have succeeded long term with only 2 of 8 specimens we planted.
Dasylirion parryanum, published in that banner year of 1911, hails from up to 8,000′ elevation in the San Luis Potosi State in Northern Mexico, where it produces 3′ tall trunks.
Dasylirion quadrangulatum (1879) hails from the Southern (warmer) end of Tamaulipas and Nuevo Leon. It is much too tender for us to grow in the open here in Zone 7b, but we’ve kept it alive for a couple of decades by siting it in a microclimate adjacent to a brick wall house foundation. It is one of only two species lacking leaf spines. With great age, it produces trunks to 9′ in height.
Dasylirion serratifolium, first described in 1838, is from Oaxaca, Mexico, where is grows on rocky, alkaline hillsides to 6,600′ elevation. The location and elevation means it really shouldn’t survive our winter. That said, our only remaining specimen below is now 20 years old, but is still far from reaching the 6′ tall trunk height it does in the wild.
Dasylirion texanum (1850) is another very winter hardy species, found on rocky slopes, ranging from Central Texas into the mountains of Northern Mexico. It is one of the shortest species, with a trunk that doesn’t exceed 1′ tall.
Dasylirion wheeleri, first documented in 1878, ranges from Texas, Arizona, and New Mexico south into the mountains of Northern Mexico. It matures at 6′ tall, and in situ, can be found in both grasslands as well as openings in pine/oak forests. It is another of the most cold hardy species.
An old clump we planted years ago in flower is quite remarkable.
We hope you’ll limit your consumption of Sotol as a drink and instead join us in becoming an ex-situ conservation garden for this amazing genus of plants.
In 2006, NC plantsman, and our long time customer, Graham Ray of Greensboro, emailed to see if we were interested in a dwarf Asaparagus densiflorus (Sprengeri) fern that he grew in his rock garden, and had been winter hardy for several years in his Zone 7a garden.
We had already worked with several asparagus species for years, and have a great fondness for the ornamental potential of the genus, so of course, we jumped at the opportunity. We were perplexed, however, how a dwarf version of the marginally hardy Asparagus densiflorus could have survived in Greensboro, which is a 1/2 zone colder than our garden south of Raleigh.
Despite our skepticism, we planted our new treasure in fall 2006, which thrived here, despite our winter hardiness concerns, not blinking during three upcoming single digit F winters. A few years later, we sent a plant to our friend Hans Hansen at Walters Gardens in Michigan for further testing. Despite their winter temperatures well below 0F with no snow cover, it thrived there also. What was going on, we wondered, since this simply shouldn’t be possible.
Our mystery was finally resolved this summer when taxonomy researchers from the University of Georgia, working on the phylogeny of the genus Asparagus, learned of our extensive collection of Asparagus species, and came by to take samples for their research. This fall, we got word that our dwarf plant which we had named Asparagus ‘Graham’s Cracker’, was in fact not a selection of the common hanging basket species, Asparagus densiflorus, but was instead a seedling of the Zone 4 hardy Asparagus cochinchinensis.
As we re-traced the plants origin, it turned out that Graham had purchased the plant here at Plant Delights, as a dwarf seedling he found in one of our sale house flats, which our staff had failed to notice.
Above is a photo of a mature plant of Asparagus ‘Graham’s Cracker’ at JLBG, which has finally reached a whopping 15″ in height…a perfect plant for the rock garden or in larger bedding schemes. Like the species, the fall foliage is a brilliant gold.
And here’s mama, Asparagus cochinchinensis ‘Chuwang’.
I’m just back from a recent plant trip to coastal Virginia and wanted to share some trip highlights and photos. Mark Weathington of the JC Raulston Arboretum and I headed north for a quick 2 day jaunt to the Norfolk area of Virginia.
Our first stop was the garden of long time garden friend, Pam Harper. For decades, Pam was probably the most prolific and knowledgeable garden writer in the country, in addition to having what was once the largest horticultural slide library.
At 92, and despite suffering from debilitating eyesight issues, Pam still gardens, including planting and pushing carts of mulch around the garden. It was such a joy to once again walk her amazing garden, listening to the both the historical details and performance of each plant we passed.
Pam was donating the remainder (20,000) of her slide collection, which previously numbered over 100,000 images, to the JC Raulston Arboretum. There, they will be digitized for public availability.
Her 45 year-old Camellia sasanqua ‘Yuletide’ was the largest either of us had ever seen.
We both also fell in love with Camellia x vernalis ‘Meiko Tanaka’…a plant we’d never encountered in flower, but seems to have good commercial availability.
The gold barked Japanese maple, Acer palmatum ‘Bihou’ was also showing off its stunning winter color.
Pam’s garden has always yielded some of the most amazing Arum italicum seedlings I’ve ever seen. We are already growing two of her selections in hopes of future introduction, but we found a few more that we couldn’t resist.
Our next stop was the Virginia Tech Tidewater Arboretum at the Hampton Roads Experiment Station. It had been many years since either of us had visited.
What we found was an amazing plant collection that has been mostly abandoned, except for some minimal mowing maintenance. In most cases the labeling was somewhat intact, although some required Easter egg-like hunts, and others were simply nowhere to be found.
The late Virginia Tech researcher, Bonnie Appleton had worked to get homeowners to plant shorter maturing trees under power lines. To make her demonstration more authentic, she had faux power lines installed, which you can make out among the branches. It was interesting to see that virtually all of the plants she promoted as dwarf, had all grown well into the power lines. Mark recalled conversations with her decades earlier explaining that her choices weren’t really very sound.
There were a number of amazing older specimens including one of the largest Quercus polymorpha (Mexican Oak) that we’d ever seen in cultivation. This 75′ tall specimen dated to 1989, was originally gifted to them by the late JC Raulston, from a Yucca Do Nursery wild collection.
The old specimens of Ilex buergeri were absolutely stunning. This is a beautifully-textured, spineless broadleaf evergreen that’s virtually unknown in the commercial trade.
Another spineless holly, Ilex pedunculosa (long-stalk holly), is known for being difficult to grow in our hot, humid climate. Their specimen, however, looked absolutely superb.
We caught Fatsia japonica in full flower…always a great nectar source for honeybees in the winter months.
A highlight for me was catching the amazing stinkhorn fungus, Clathrus columnatus in full splendor…both visually and odoriferously.
Leaving the Hampton Roads station, we headed to the Norfolk Botanical Garden, where Mark worked before he came to the JCRA. Much of their efforts in the fall and winter are put toward their massive winter lights festival.
Norfolk Botanical Garden is home to an extensive and renown camellia collection, so we spent a good bit of time roaming the woodland garden where they grow. We were particularly interested in their Camellia species collection, several of which had questionable labeling. Here is one that was correct, Camellia gaudichaudii.
We spent a good bit of time studying a holly, labeled Ilex purpurea (syn. chinensis). The plant was amazing, but looks nothing like that species. Hopefully, a holly expert will be able to help us identify it from our photos.
This was my first time seeing the self-fertile idesia, Idesia polycarpa ‘Kentucky Fry’. I can’t imagine why this amazing, easy-to-grow plant isn’t more widely planted. I can think of few trees with more winter interest.
The shrub/small tree that blew us away from several hundred feet was a specimen of Arbutus unedo ‘Oktoberfest’. We’ve grown Arbutus unedo ‘Compacta’ for decades at JLBG, but have never seen anything as stunning as this clone.
While we’re talking about plants with red fruit, I was fascinated with their specimen of Cotoneaster lacteus. I had mistakenly assumed that most cotoneasters fail in our hot, humid summers, but obviously, I’ve never tried this species, which is typically rated as hardy only to Zone 8a. I think we need to trial this at JLBG.
Finally, I was particularly fascinated with a Quercus nigra (water oak), that formerly had a planter built around it’s base. As you can imagine, the tree roots made short work of the planter, but once the planter boards were removed, the resulting tree root sculpture is simply exquisite.
I hope you’ve enjoyed the highlights of our recent trip.
Great new plants for the garden do sometimes just happen. They can occur as a spontaneous sport from an existing planting, as a seed selection that has much better garden traits, but many of our most useful and ecologically important plants in the garden have their start in exploration. I was thinking about this today as I observed the tightly-clumping overwintering rosettes of one of our newest introductions to the JLBG—Oenothera riparia, Riverbank Sundrop.
Sundrops hold a special place in my heart. My grandmother loved them and had large swathes of the old pass along yellow standard Oenothera fruticosa/tetragona in her extensive garden. Every June they would burst into flower for a brief week or so, bringing a brilliant light and foil to her many glorious iris. As I mature, I have come to value plants with connections to our being but also the value of similar plants that can provide the same nostalgia while giving us much more in the landscape.
A plant known as Riverbank sundrops may be a perfect example of a great garden plant that is native to the Southeast and provides more of what gardeners love, while also providing the native insects and other wildlife an abundant resource.
Oenothera riparia was described by Thomas Nuttall in 1818 from plants collected along the Cape Fear River near Wilmington, NC. Nuttall provided a very full description of the plant (for the time) though he presumed it to be a biennial—it is in fact a long-lived perennial. J.K. Small recognized the species in a segregate genus as Knieffia riparia in his 1903 Flora of the Southeastern US. In 1937, Munz reduced the species to varietal status as Oenothera tetragona ssp. glauca var. riparia, and after this it was essentially lost to the minds of taxonomists and plant enthusiasts being considered merely part of the immense variability of Oenothera fruticosa by Radford, Ahles and Bell (1968).
In the mid 1990’s while working in the tidal freshwater swamps and marshes of South Carolina, Richard Porcher and I encountered this species growing at the bases of Bald Cypress trees, on stumps, and on floating logs just above the high-water tidal line on the Waccamaw, Pee Dee, and Edisto Rivers. My frustration with its identification led me to the name Oenothera riparia and its recognition as a completely and consistently distinct taxon—which is very unusual in a genus known for its morphological variability and messy taxonomy.
This plant is smooth (lacking hairs) throughout with thick textured dark-green leaves and a very bushy habit—it does not produce long stolons or rhizomes, so it forms a dense clump. The stems generally range from a foot to nearly 3 feet in height and the thick stems become semi-woody, providing a stiffly upright growth form. Rather than a single burst of flowers this species produces masses of flowers over the entire summer (June-late August) with sporadic flowering later in the season.
Imagine, here we could have a sundrop that won’t spread like wildfire, doesn’t flop, and flowers for month after month! Sounds like everything you would want in a plant. There is only one problem, it hasn’t been cultivated. This is where the adventure continues and as we embark on this adventure, I would like to take you along for the ride. There is so much that goes into identifying a potentially great garden plant, evaluating it, and bringing it to the trade.
Our initial collections were made this August (2022) when Zac Hill, my wife Waynna, and I were traveling through the SC coastal plain. We made the stop at the Edisto River in Colleton County where I had seen the plant many years before and just like I remembered, there they were, full of seed and with some flowers still present. The only problem is that they were growing far out in the water along the bases of trees! The Edisto is a blackwater river with a large tidal amplitude at this location and it was full on high tide. If you’re a field botanist you forget entirely about the things that concern other more rational folks, like the multitude of large Alligators, and make for the plants. I found some low branches on a neighboring willow tree that kept my feet in only a couple feet of water, and balancing on the branch, in the water, made my way all the way to the edge of the river where a fabulous floating log provided an abundance of seeds and two small plants from a large cluster of individuals. The only casualty was my prescription glasses which promptly fell from my head into the depths of a rapidly moving Edisto River (my wife will not easily let me forget the cost of this single collection). The first step in the process of bringing a new plant into production is done.
Our two small divisions were placed directly into the sun garden at JLBG and the seed was sown. For this plant to be successful in a garden it must be able to not just survive but thrive in a common garden condition far away from its very narrow niche at the very upper edge of the water along the Edisto. You might think this would be unlikely, but other incredible garden plants are entirely found in wetland communities and thrive under very different conditions in the garden. A good example of this is found in another of our introductions, Eryngium ravenelii ‘Charleston Blues’, which comes from high pH wetlands not too far away from the Edisto River.
Will it be hardy here? Will it survive under normal garden conditions? Will it maintain its distinctive and garden-worthy features? Well at least part of this can be answered already. Our tiny divisions are now large overwintering basal rosettes. The plants have not thought about running away from their tight cluster, and they grew very well during their first autumn in soil that was not kept overly moist.
The real test lies ahead. What will the plants nature be under cultivation? Will it be as good as I think it could be? Will it be better? One can only hope, put in the labor, and follow along to find out the end of this story for Oenothera riparia. It could provide all of us with a stately and handsome bit of nostalgia with far greater design and utilitarian use for humans and our native biota. What’s more, there are other seemingly great garden-worthy Oenothera out there—not in far-flung locations but right here in the Carolinas. Have you ever heard of Oenothera tetragona var. fraseri? If not, look for us to tell you more about that in the years to come, there’s a fantastic form with huge flowers in the Blue Ridge escarpment of South Carolina!
The cold and raw weather of late autumn and winter provide the perfect opportunity to sit down with the dissecting scope and put our ferns through the identification mill. Often gardens and nurseries receive a plant into their collections from an exporter or collector who has put their best guess on the identification. After many years in cultivation, we realize what we thought was the right species name for our specimens is incorrect. Today’s nasty weather provided the opportunity to examine, in detail, one of our favorite evergreen fern groups – Dryopterissection Variae.
These firm-leaved evergreens produce thick-textured, durable, medium-sized fronds of varying shape but all display a noticeably longer basioscopic pinnule (that’s fancy talk for the lowest, innermost segments of the divided leaves). All members of the section that we have grown have proven to be very adaptable to our hot, humid summers and unpredictable winters if grown in shade or partial shade in moist woodland garden conditions. The fronds tend to burn if they receive too much light. They are late risers in the spring often not producing a new flush of leaves until late spring or even early summer.
At the beginning of the day, we started with 8 accessions of Dryopteris varia, 2 accessions of Dryopteris bissetiana, 6 accessions of Dryopteris formosana, one accession of Dryopteris saxifraga and a couple of unknowns. From these numbers you would expect that the one plant we would know best would be Dryopteris varia.
Well…it turns out all the plants we had received or had identified as D. varia were actually representative of other taxa. If you’ve never tried keying ferns using The Flora of China or The Ferns and Fern Allies of Taiwan, you would have no idea just how difficult a process this is. The floras of these areas are notoriously difficult to use and often contradictory or difficult to assess using illustrations or pictures (yes even plant taxonomists google names to find images). Very quickly we became intimately familiar with the nature of the stipe and rachis scales, frond outlines, and disposition of the vestiture (yeah you think that sounds easy, right?).
We found most of our collection was actually composed of Dryopteris bissetiana, which are mostly from collectors who sent us tentatively identified wild-collected material. The majority of these were from Sichuan in China, however one very beautiful, deep green and glossy selection that is only half the size or less of the others was Tony’s collection in Korea, and has tentatively been identified as Dryopteris saxifraga. All of these are remarkable garden plants, but we are very excited to some day offer the choice dwarf from Korea which we have named ‘Cheju Dwarf.’
It was a pleasant surprise to find that our collections of Dryopteris formosana were correctly labelled, but we weren’t prepared for there to be two distinctly different looking plants represented in our garden that are the same species.
One of these is the plant that has been shared among fern enthusiasts for some time that is the typical sexually reproducing diploid. The other is an apogamous triploid that looks like a completely different species. In a diploid (like you and I) the pairs of chromosomes uncouple and one copy of each goes into making the male and female gametes.
Thus, each gamete has only one set of each chromosome (haploid) and when combined with those from the complementing sperm or egg results in another diploid. Plants sometimes have a mistake in their cells that lead to the production of gametes with twice as many chromosomes as they would normally have and when such tetraploid plants breed with a diploid the result is a gamete with 2 copies of each chromosome combining with a gamete with only one—thus triploid. In your average plant this triploid is a dead end for reproduction by seed or spore because they have an uneven base number 3—which can’t be divided into an equal number of chromosomes, so it is sterile.
This triploid avoids the curse of having an uneven number of chromosome pairs by avoiding sexual reproduction and producing spores that will result in new plants without the traditional interplay of sperm and egg on a germinated gametophyte (yes apogamy in ferns is still legal in all states and countries). We were puzzled when two very different looking ferns keyed to the same species. Everything that was in the key matched. The bullate hairs, the shape, the color, the basioscopic pinnae and the overall shape.
Our taxonomist, Zac Hill, very quickly uncovered a recent paper by Kiyotaka Hori, et al (2017) which explained and beautifully illustrated our conundrum. The triploid produces a wider, far more pentagonal frond with a less erect nature in the way the blade is held, and a deeper green, highly pleasing color—now that’s pretty darn cool! This new discovery we have named ‘Yushan 2 X 4.’ A new plant for us all to grow in the years to come and now you know why we chose the name diploid (2) X tetraploid (4).
Now that we realize we grow seven different forms of Dryopteris bisettiana, each collection will be given a cultivar name, which will refer back to their specific origin and uniqueness.
Every day brings discovery when you manage a collection of 30,000 taxa but one thing we know for sure, these are amazing, well-behaved, slow growing woodland plants that are the essence of what makes Juniper Level Botanic Garden so amazing.
Patrick McMillan, director of horticulture and gardens
Hori, Kiyotaka, L. Kuo, W. Chiou, A. Ebihara and N. Murakami. 2017. Geographical distribution of sexual and apogamous types of Dryopteris formosana and Dryopteris varia (Dryopteridaceae) in Taiwan. Acta Phytotax. Geobot. 68 (1): 23-32.
One of our favorite palms for the garden is the US native Sabal minor var. louisiana. While it can’t outgrow the Himalayan Trachycarpus fortunei (windmill palm) for speed of developing a trunk, Louisiana palmetto is the most winter hardy of all trunking palms. One of the mysteries is that in the wild, the same population can have both above ground as well as subterranean trunks.
Our garden specimen in the photo below was planted from a 1 qt. pot in 2005. Eventually, Sabal minor var. louisiana will develop an above ground trunk, which on our specimen below is just beginning.
The background on Sabal minor var. louisiana is a botanical mystery. Some taxonomists consider it a valid species, while others consider it variety of the subterranean trunked Sabal minor. Others consider it to be an old hybrid of Sabal minor and either Sabal mexicana or Sabal palmetto. A similar hybrid, Sabal x brazoriensis from near Dallas, had its DNA analyzed several years ago, and was found to be an old hybrid of Sabal minor and a now extinct population of Sabal palmetto.
Sabal sp. ‘Tamaulipas’ from Northern Mexico is another mystery palm in need of some family history work. Thankfully, palm researcher and grad student, Ayress Grinage at Cornell has begun to look at these mystery sabal palms to figure out how they came to be. We, and others have sent material, and now await the results of the paternity test.
In 2014, we decided our goal for the years’ century plant breeding project was to see how large a Zone 7b winter hardy agave we could create. We had seven agaves flower that year, but only two had the epic proportions we required.
One of those was a selection of Agave x protamericana from a Yucca Do collection in Northern Mexico. By the time of flowering at 15 years of age, it had reached 5′ tall x 9′ wide.
Agave x protamericana and Agave americana are the two largest blue-foliaged agaves, but only Agave x protamericana is winter hardy for us, here in Zone 7b, since it also has some ancient genes from the hardier Agave asperrima, which adds slightly to its winter hardiness. You can distinguish the two plants by feeling the back of the leaves. Agave americana has smooth leaf backs, while Agave x protamericana has sandpapery leaf backs. The largest size listed for Agave americana in Howard Gentry’s Agaves of Continental North America, is 6′ tall x 12′ wide.
At the same time we had a blind flower shoot on our giant Agave x pseudoferox ‘Bellville’. Agave x pseudoferox is another ancient Mexican hybrid in need of a DNA workup. We think it’s probably a hybrid of Agave x protamericana with Agave salmiana var. ferox and possibly Agave gentryi). Commercially, it’s usually called Agave salmiana var. ferox, which is similar in appearance, but with absolutely no winter hardiness.
Prior to full flowering at 15 years of age, our giant specimen of Agave x pseudoferox ‘Bellville’ had reached a mature size of 4′ tall x 8′ wide. We were able to make the cross prior to it fully flowering, by using something we mentioned above that we call “blind shoots” or boners.
Being monocarpic plants, the rosettes of most agave species die after flowering, but side shoots are an interesting phenomenon we see on all of our Agave x pseudoferox cultivars and hybrids. These “blind shoots” emerge from underground stolons instead of from a rosette. They are much shorter than normal flowering shoots which emerge from the rosettes (2′ tall vs. 20′ tall), and they have no impact on the life expectancy of any of the rosettes.
In the case of Agave ‘Bellville’, our plant began producing blind shoots five years prior to the clump producing a full size, rosette-based flower stalk. The beauty of blind shoots is that they breed and pass along characteristics of the parent without the need for a tall ladder.
We gave our hybrids the seed strain cultivar name, Agave ‘Bluebell Giants’. From these, we selected 23 clones, which were planted in the trial fields in 2016. Of those, only 4 survived our subsequent trials for winter hardiness.
Our best and most winter hardy seedling from the cross pictured below is now 6 years old in the garden. We’ve given this the name Agave ‘Supersize’. It has achieved a size of 6′ tall x 8′ wide in that time. To put this in perspective, it is larger at 6 years old than both parents were at 15 years old. If Agave ‘Supersize’ waits until age 15 to flower, it could easily reach more massive proportions that any Zone 7b winter hardy agave in existence.
Gardeners typically curse fall leaf drop, but ginkgo trees often get a pass, not only because the golden fall leaves look so great on the tree, but they also look great on the ground, not displaying the disheveled look of other larger tree leaves. Here’s our ginkgo tree, planted just in front of our office, that’s been putting on quite a show for the last few weeks.
Despite what most folks think, the genus Ginkgo is indeed a North American native, but to understand that, requires a bandwidth that many native plant purists simply don’t have. Native is not a place in location, it is only a place in time. The first Ginkgos date back to the lower Jurassic period about 190 million years ago, when the genus was born in Mongolia. From there, it migrated around the world, based on dramatic climate change, with fossils found from what is now the UK to the US (Oregon to North Dakota).
Ginkgos continued to diversify through the Cretaceous period (65-145 million years ago), when they reached their maximum distribution, with 5-6 species currently recognized. By the Paleocene (56-66 million years ago), all of the species but one had gone extinct. Although that remaining species is known as Ginkgo adiantoides, it is almost identical to today’s Ginkgo biloba.
During the Oligocene (23-34 million years ago), Ginkgos moved south from their more northerly range, with the genus completely disappearing from North America around 7 million years ago. According to the fossil records, Ginkgos subsequently disappeared from Europe around 2.5 million years ago. The only vestiges of the genus that remained, holed up in three distinct refugia (botanical hideouts) in China until humans began to spread them out again and re-populate the rest of the now Ginkgo-less world. They returned to the Flora of both North America and Europe in the 1700s.
For those who want to dive deeper into the Ginkgo story, here is a link and another.
While we leave all the fancy mangave creations to our friend Hans Hansen at Walters Gardens, we continue our work on creating more winter hardy (to 0 degrees F) hybrids. Over the last couple of years, we’ve made several crosses using some of Hans’ hardiest Agave ovatifolia based F1 generation selections, like xMangave ‘Blue Mammoth’ and xMangave ‘Falling Waters’ and crossing them back onto Agave ovatifolia.
The F1 mangave hybrids from Hans’ work, have all lost the monocarpic trait of pure agaves, meaning they will not die after flowering. We are curious what will happen if the hybrids have 2 parts agave and one part manfreda. With most of our crosses, we grow 100-200 of each into 1 qt pots, which allows us to do an initial culling after seeing the juvenile foliage traits.
The photos below are from that process, which happened this week. This is a cross of xMangave ‘Falling Waters’ x Agave ovatifolia ‘Frosty Blue’. The first image shows the diversity in the seedlings. All plants have some degree of glaucous foliage…some more toward blue and others with purple spotting that comes solely from the Manfreda parent. It was interesting that the F2 plants still showed some degree of purple spotting…probably around 5% of the plants.
From a batch of 100-200 plants, our goal is to select 10% for the next round of in ground trials. We focus on selecting at least one plant for each desirable trait. Those traits include: size (dwarf or large), leaf undulations, spotting density, best blue color, leaf twisting, leaf length, leaf width, overall form, best spination, and variegation.
Below are some of our final selections for the next phase of trials. These will be up-potted into 3 quart pots and overwintered indoors, since we’re already too late for planting outdoors this year. These will go into the ground in spring, after the danger of frost has passed.
I’ve been very blessed on several UK visits to spend time at the amazing Ashwood Nursery of plantsman John Massey. One of the real treats of each visit is a chance to spend time in John’s private hepatica greenhouse. To say John is a bit obsessive about the genus is a grand understatement, so it should be no surprise that he has channeled all that knowledge into a new Hepatica book, that’s hot off the press.
We first learned of John’s obsession with the genus, when he joined us on a 2000 expedition through NC, SC, Alabama, and Tennessee to study the hepatica in the wild…along with our main goal of studying trillium. Below is an image from that expedition. Hepatica are also native to Asia.
Our copy of My World of Hepaticas arrived recently, and John’s book is a massive 296-page compendium of pretty much anything you’d want to know about hepaticas, compiled from John’s decades of work with the genus. John’s writing style is easily readable, coming across as if you’re having a relaxed conversation over dinner, and the incredible photos are an equal match to the text. Right now, you can only obtain a copy by ordering it from the Ashwood website.
Nurses and plant taxonomists are among the few fields in which you would run into the term, anastomosing veins. Having been in the plant world all my life, I had never even run into the term until trying to key our some bamboo ferns in the genus, Coniogramme, almost a decade ago. It turns out that to distinguish between species, you need to determine if the spore patterns on the back of the leaf have an anastomosing or parallel vein pattern. Anastomosing veins are those which diverge and reconnect forming a pattern like a snake skin. We’ve grown quite a few ferns, but none have the amazing vein patterns of coniogramme. Below are the leaf backs of Coniogramme japonica in fall.
Starting in September, the population of imported fire ants (Solenopsis invicta) explode around the garden. The ant population dramatically increases in fall, with mounds rising several inches overnight, especially after heavy rains. The US Department of Agriculture estimates that there are currently a shocking 13,475 million tons of fire ants living illegally in the US.
Fire ants spread during mating flights, where they can rise as high as 300′ in the air. This allows the ant infestation to move up to 9 miles every year. Not only can fire ants kill plants where they build a mound, they are attracted to electricity, and are well-known for getting into underground wiring and shorting out electrical boxes.
To beat them back as much as possible, we feed the ants a bait, which the workers take into the mounds. Often within an hour, it renders the mounds inactive. Below, you can actually see them moving the bait into the mound.
What a lovely surprise to wake up recently to this Cope’s gray treefrog (Hyla chrysoscelis), who had parked itself on our front door handle…obviously, waiting for its meal to arrive. These frogs, which typically live for 7-9 years have a voracious appetite for both insects as well as other frogs.
Despite going in and out constantly through the morning, it remained in place for over 8 hours. I can only imagine the suction cups made the up and down motion of the door handle feel a bit like a ride at the fair. We assume the order from Frogs-R-Us must have arrived, since the door handle had been vacated by days end.
Elliott’s aster (Symphyotrichum elliottii) is the absolute last of our asters to flower at JLBG. It doesn’t begin to flower until the first of November and withstands the mild frosts of October like they didn’t even happen. It is naturally found in tidal freshwater marshes and other moist open sites from the Virginia and Carolina coastal plain south to Florida and west to Louisiana. Though it hails from moist environments it thrives under general garden conditions if the soil isn’t allowed to become too droughty.
The plant has a lot to recommend it besides the time of flower. It forms stiff stems rising 5-6’ tall crowned with a dense pyramidal arrangement of inflorescences of pale pink with a hint bluish-purple ray flowers and bright yellow disk flowers. The lack of lanky branches allows this tall aster to display its flowers without flopping all over the rest of your garden in the manner typical of asters. It spreads via rhizomes, so you need to be sure to give it space to roam a bit. It provides a dramatic impact when planted at the back of borders. Though it spreads, it doesn’t roam far from the parent plant and can be easily kept in place by yearly thinning of the outer edges of the clumps.
The most outstanding feature of this beautiful aster to me is the number and diversity of pollinators it supports. I don’t think I’ve ever seen a plant that attracted more. In addition to swarms of honeybees, bumblebees, carpenter, and solitary bees the flowers draw in numerous pollinating flies, halictids, moths and skippers. I love plants that extend the color season and though we all think about early spring, we really should also plant to extend our love affair with color into the leafless season and Elliott’s aster does this is a big way.
Juniperus communis is a common landscape juniper with a wide natural distribution…one of the widest of any woody plant in the entire world.
In the North American part of its range, it’s widespread throughout the Western US, and across the northern tier of the country all the way to Maine. East of the Mississippi River, however, it’s virtually not-existent south of the Great Lakes.
Patrick McMillan had been telling us about a population he rediscovered from an earlier Henry William Ravenel (1814-1887) documentation of a single clone growing naturally in Aiken, South Carolina. Last week, we made the 4 hour drive to visit this ancient living fossil. Here is all that remains, growing in an amazing nature park, known as Hitchcock Woods, where it grows surrounded by a forest of Kalmia (mountain laurel).
We have this propagated and growing at JLBG, and hopefully in the future, when our plants get larger, we can share these amazing genetics with a wider audience.
Gardens mean different things to different people, so we were pleased to recently host a series of Plein Air painting classes at JLBG. Here are the participants from Alia Fine Arts Studio with visiting artist, Christina Weaver, studying their finished works after the three day painting/studying session.
We are always interested in checking out the offspring, when plants in the garden have unexpected romantic rendezvous with their distant cousins…often when we least expect it. We have found arums tend to be quite promiscuous in the garden. While most offspring go to the great compost pile in the sky, a few are worthy of adoption and naming.
Below is our selection of a cross of Arum dioscorides x Arum italicum that we named Arum ‘Love Child’. While the foliage resembles typical Arum italicum, the spring-borne flowers show great influence of Arum dioscorides with the purple spotting inside the spathe. It’s our hope that Plant Delights will have a first crop of this new hybrid to share in the 2023 catalog.
This week, we fielded a call from our garden staff that there were large yellow jacket (Vespula maculifrons) nests in several arborvitae near where they were working. Knowing how aggressive and toxic the stings of these native vespid wasps can be for humans, they had requested help in getting the nests eliminated.
When Patrick arrived to check out the problem, he noticed that instead of finding nests, the yellow jackets were actually feeding on the arborvitae. Since this species of arborvitae was currently in the midst of pollen and cone production, there also appears to be some type of resin being exuded at the same time, which is a delicacy for the yellow jackets.
We estimate there were between 100 and 200 yellow jackets per plant. Because they were busy feeding, they had no interest in us, despite our close up study of their behavior. Our entomologist, Bill Reynolds, who had observed this phenomenon before with vespid wasps and arborvitae, showed us that we could actually touch the yellow jackets without drawing their ire. This is certainly not the case if you’ve ever been anywhere near a yellow jacket nesting site.
The other interesting phenomenon is that despite being Eastern US natives, the yellow jackets were only interested in the Asian arborvitae species, Platycladus (Thuja) orientalis. Growing adjacent was the East Coast and West Coast arborvitae, Thuja occidentalis and Thuja plicata, but neither attracted a single insect. This is another nail in the coffin of that oft repeated myth that only native plants feed native pollinators. One of many lessons here, but it’s especially important not to spray first and ask questions later.
History is replete with examples of new plant species that are first encountered by intrepid plant explorers, yet described later by taxonomists. Salvia darcyi was discovered and introduced into cultivation by Carl Schoenfeld and John Fairey of Yucca Do Nursery. Three years later, they guided researchers to the site who subsequently described the species without acknowledging the original collector. It is unfortunate that the act of discovery by those in horticultural circles are so seldomly recognized (not to mention the indigenous peoples who have known many of them for eons).
Upon my first visit to Heronswood in the autumn of 2019 I was shown a splendid robust Begoniawith heavily lobed leaves, short upright stems, and amazing tight-clumping habit with yellow (yes yellow!) flowers. I immediately confirmed that this was a heretofore undescribed species. The plants had been grown from the seed collection made by Dan Hinkley along with fellow collectors and nurseryman, Shayne Chandler and Leonard Foltz, from Arunachal Pradesh India. These plants were shared by Mr. Hinkley with Monrovia who immediately released it under the name TectonicTM Eruption Begonia (Begonia sp. DJH18072).
The unknown Begonia has now been given a formal scientific name Begonia lorentzonii by Swedish taxonomist Eric Wahsteen and the Indian researcher Dipankar Borah, based on two specimens collected by Borah in November of 2018 (incidentally, after Dan Hinkley’s collection). No mention of the plant in cultivation or the contribution of Dan is found in the publication despite the fact that quite a few of the Begonia aficionado crowd around the globe had by then become familiar with the plant. Regardless of the name, this species is among the most spectacular hardy garden plants for cool but not cold climates.
Begonia lorentzonii has proven hardy at Heronswood (zone 8a) where it was left outside with only a covering of leaves and straw in temperatures ranging into the low teens and at least a week long stretch of consistently below freezing temperatures which resulted in ground freeze. It forms 2-2.5’ tall dense clumps with one of the best forms I’ve seen in a cold hardy species.
In late summer through late autumn it is adorned with yellow flowers beset with hairlike projections on the outer surface of the tepals produced on stems that equal or are slightly shorter than the leaves. Begonia lovers should visit the Renaissance Garden at Heronswood to see mature plants in their full glory and a pilgrimage to Heronswood is a must for all hardy Begonia lovers as the collection of rare and unusual cold hardy species is probably the best among our public gardens. While this startling plant appears to be perfectly adapted to life in the mild Pacific Northwest it remains to be seen what its tolerance for heat will be. It was an honor and pleasure to grow and nurture these plants during my time at Heronswood and I must admit my heart and mind will forever be drawn to that sacred space of ground whenever I glimpse a Begonia of any species.
Last week, we were repotting our container agaves prior to winter, when we ran up on this unusual sight. Let me begin by explaining that there are three groups of agaves, based on how they propagate: solitary agaves, rhizomatous agaves, and offsetting agaves. While it’s not unusual for a rhizomatous agave to produce an underground shoot in container, this level of underground shoots is highly unusual. What is even stranger is that this is a non-rhizomatous cultivar.
Since some agaves are poor or non-offsetters, the only way to force them to multiply is to remove the apical bud, either by means of coring, or drilling. Once this is done, the agave usually forms offsets in the remaining leaf axils. For some reason, when this plant of Agave ‘Ripple Effect’ was cored, it went nuts by developing underground rhizomes.
Left to its own devices, there will be one plant produced from the growing tip of each rhizome. There is, however, a dormant bud every few inches along the rhizome, so in theory, this could produce hundreds of plants if we can figure out how to make the dormant buds break. Below are the shoots after we unwound the twisty rhizomes.
Our 2016 century plant hybrid is looking quite lovely in the garden this month. This plant, which we named Agave x victorifolia ‘Prince of Whales’, is a hybrid of the Whale’s tongue century plant, Agave ovatifolia (male parent), and the Queen Victoria century plant, Agave victoriae-reginae (female parent).
Since both parents are non-offsetting, this means that the offspring will grow to maturity, flower, then die. Consequently, in order to be able to propagate and share, we will have to drill out the central core of the plant to trick in to offset. While this ruins the appearance of the original, it’s the only way for this to ever be shared and preserved. This plant has been in the ground since 2018, so we expect to have another eight years (guessing) prior to flowering. Consequently, so we’ll probably gamble on waiting a few more years before performing surgery. Winter hardiness is Zone 7b-10b.
Chamaecyparis ‘Red Velvet’ is a juvenile-leaved selection of our native white cedar, Chamaecyparis thyoides, discovered and introduced by Florida’s Blue River Nursery. This recent introduction looks similar to the 1960s introduction, Chamaecyparis ‘Rubicon’, except that ‘Rubicon’ dies in the garden on a bad day, and on a good day looks like death would help it. Chamaecyparis ‘Red Velvet’, on the other hand, is a superb garden plant.
So, why is this the case? Well, there are two distinct forms of this US coastal native wetland species, Chamaecyparis thyoides. Some botanists recognize the southern ecotypes as a separate species, while other make no distinction. We agree with those who recognize the southern plants as a subspecies,.Chamaecyparis thyoides ssp. henryae, which has a natural distribution centered in the Florida panhandle, and is dramatically easier to grow in the garden. Chamaecyparis thyoides ssp. thyoides, which ranges from Maine to Georgia, is much more difficult to grow in most garden conditions.
Because white cedar is native to cool fresh-water wetlands, very few cultivars perform fine in average to moist garden soils, while others fail miserably. What we need are more selections of the better adaptable Chamaecyparis thyoides ssp. henryae. The only named cultivars we know to exist is Chamaecyparis ‘Webb Gold’, and the afformentioned Chamaecyparis ‘Red Velvet’.
The cultivar ‘Red Velvet’ matures at 12-15′ in height. Our four year old plants have reached 6′ in height. In winter, the foliage color changes from green to a reddish purple, hence the name. Thanks to Georgia conifer guru, Tom Cox for spreading this amazing selection around to collectors and nurseries. Estimated winter hardiness is Zone 7a-9b, and probably much colder.
How many folks are growing Hypericum hypericoides (St. Andrew’s cross)? The name translates to hypericum that looks like a hypericum….duuuh. We love this native shrub which hails from New Jersey southwest to Texas. St. Andrew’s cross typically matures at 2.5′ tall x 5′ wide and adorned from May through September with small, light yellow flowers, which form an “x”, hence the common name.
In the wild, Hypericum hypericoides is usually found in slightly acidic to slightly alkaline sandy soils, often in pine savannas, but in cultivation, they seem quite adaptable to an array of garden conditions from sun to part sun. In form, it resembles a Helleri holly with yellow flowers. The photo below is a 2 1/2. year old plant at JLBG. Winter hardiness should be Zone 6a-8b at least.
Few plants I’ve ever grown enchant me like Forestiera angustifolia ‘Woodlanders Weeping’. This incredible weeping selection of the Texas native is typically known as a scraggly upright bush that grows in dry alkaline soils. This special form was discovered in Calhoun County, Texas in 1992 by our friend Bob McCartney and the late Texas plantsman, Lynn Lowrey. In 1996, Bob, Lynn, and Patrick McMillan returned to the site for cuttings. It was subsequently propagated and introduced by Woodlanders Nursery. Surprisingly, it also thrives in moist acidic soils, and seemingly has no garden conditions where it doesn’t thrive.
We actually enjoy the incredible structure of the deciduous bare stems more in the winter time without the tiny deciduous foliage. The photo above was just taken at JLBG in late September. Mature size is 6′ tall x 25′ wide, so be sure you have a large enough space. I would think this is a plant that would be embraced by every native plant nursery, unless they have one of those bizarre hang-ups that man-made state political borders matter. Winter hardiness is unknown, but at least Zone 7b-9b.
We love the genus Hydrangea, but are really fascinated by those at the far end of the family tree. While most hydrangeas flower in late spring, we actually have a couple flowering now we’d like to share.
The first is Hydrangea involucrata, a native to both Japan and Taiwan. The word “involucrata” indicates it has some serious involucres (the bracts surrounding the inflorescence). The first image shows the plant in bud, the second in full flower, and the third image is after the flower color has faded. All three stages are on display at once in the garden this week. They typically reach 6′ in height and width. Winter hardiness is Zone 6a-8b.
Hydrangea amamiohshimensis (below), from Japan’s southern Ryuku Islands, was once considered a hydrangea cousin, until a 23andMe test confirmed it was actually a true hydrangea. Prior to the test, it belonged to the genus Cardiandra, which was effectively a perennial hydrangea, dying back to the ground each fall like most perennials. It too is in full flower in the woodland garden this week. Perhaps now that it has a recognizable name, more folks will be willing to grow it. This is the only one of the four former cardiandra species that has survived in our climate.
Now that fall has arrived, we’re all enjoying peak plume season for many of our favorite ornamental grasses. Unfortunately, there are a few significant mix-ups in the trade. The top photo is our native Eragrostis spectabilis, known as purple love grass. I’ve long admired this beautiful, but short-lived native, but have declined to offer it because of its propensity to seed around much too vigorously in the garden. In prairie restorations or less-tended gardens, it can be a spectacular addition. Hardiness is Zone 5-9.
Because most nurserymen aren’t plant taxonomists, you can perform a Google images search and find several on-line vendors who pretend to offer Eragrostis spectabilis, but show photos of the grass below, known as Muhlenbergia capillaris. Who knows which of the two they are actually selling.
If that’s not confusing enough, the plant below is known in the trade as Muhlenbergia capillaris or Gulf Coast muhly grass/pink muhly grass. The only problem is that this is actually a different muhlenbergia species. All of us have taken this name for granted, but as our Director or Horticulture/Gardens, Patrick McMillan taught us, all commercial plants labeled as such are actually Muhlenbergia sericea. We are updating our records and this name change will be implemented in the near future.
The misidentification originated with a Florida taxonomist, who mistakenly lumped three muhlenbergias together…a problem that can occur when you only study dead/smashed plants in a plant herbarium. As it turns out, the two plants, Muhlenbergia capillaris and Muhlenbergia sericea (also formerly known as Muhlenbergia filipes) are nothing alike.
The true Muhlenbergia capillaris is a rather homely plant that few folks would want in their garden. Muhlenbergia sericea, on the other hand, is a stunning ornamental plant, commonly known as sweet grass, and used for making those amazing hand-woven baskets that you find for sale in towns like Charleston, SC.
Such nomenclatural faux pas take decades, at least, for nurseries to get the names corrected since the public knows and purchases plants under the wrong name. This problem is far too common. The shrub, Ternstroemeria gymnanthera, was originally mistakenly identified as Cleyera japonica, and that mistake still persists over five decades later. Most gardeners despise name changes, often not realizing that many instances like these aren’t changes, but instead corrections of an earlier identification mistake.
You can learn more details about the mix up by reading Patrick’s article about pink muhly grass.
We are pleased to announce that Dr. Patrick McMillan’s new book, A Guide to the Wildflowers of South Carolina, has been published. While Patrick taught at Clemson, he was approached to update The Guide to Wildflowers of South Carolina (Porcher), first published in 2002.
After studying over 200,000 herbarium sheets (dead, smashed plants), and making countless trips into the field to photograph and study the plants in habitat, the updated book, A Guide to the Wildflowers of South Carolina has been born. This amazing 613-page book is a dramatic update from 2002 version, complete with more images, completely revised distribution maps, and an additional 200+ plant species.
I have known Patrick for over 30 years, and we are so blessed to have him as our JLBG Director of Horticulture and Gardens. We are the beneficiary of his encyclopedic plant knowledge every day, but now everyone can benefit from that same knowledge through this amazing new book.
His new book, which has an official publication date of next month, is available through your favorite on-line bookseller. Whether you live/travel, or botanize in NC, SC, or any of the Southeastern states, you will find this book invaluable.
It’s not unusual for ferns to have sex in the wild, even with other species in the same genus. It is, however, unusual for them to have meaningful sex with ferns of an entirely different genus. Such an odd occurrence recently happened in the greenhouses of Louisiana’s James Georgusis.
One night, possibly after a wild Mardi Gras party, a willing Phlebodium got it on with a crested tongue fern of the genus Pyrrosia. The result was a new genus of fern, x Phlebosia. It was adopted and given the cultivar name, ‘Nicolas Diamond’. At least the parents had the good sense to sexually stay within the same family, Polypodiaceae
We planted our first specimens in the garden this February, and so far, it’s growing well. The key will be to see how much winter hardiness it has…fingers crossed. Both parents are pictured below the new hybrid.
Last week, Patrick, Zac, and I spent a couple of day botanizing in the low country…i.e. Coastal South Carolina. In between swatting away the incredible troupe of mosquitos which chose to join us, we were able to capture a few images to share below.
The ancient lime sinks are fascinating. Here, old sinkholes due to subsurface limestone rock breakdown have collapsed, forming natural depressions, creating a habitat for our native pond cypress (Taxodium ascendens) and other fascinating wetland species…like alligators. Yes, we did see several, but they were too fast for our camera.
The high water marks are visible on the buttressed trunks of bald cypress.
Much of the region is, or was, a pine/grass habitat. The pines could either be longleaf (Pinus palustris) or slash pine (Pinus serotina) .The dominant grass is known as wiregrass, aka: Aristida beyrechiana.
On the dry sand ridges, we saw these piles of fresh sand adjacent to a nearby tunnel entrance. These are homes to the rare gopher tortoise, which live in the region. Patrick tells me these tortoises will use the same underground lair, which may stretch 40′ long and 10′ deep, for up to 60 years.
Gopher tortoises only emerge from their tunnels when temperatures are between 80 and 90 degree F. Sure enough, we were able to wait and get some images of these amazing creatures.
Another surprise spotting was a bright orange mutant katydid. Our entomologist Bill Reynolds tells me these are crazy rare, and worth well north of $1000 to collectors. Who knew?
Yes, we also saw some cool plants. Asclepias obovata is a little-known milkweed that’s quite rare in South Carolina, so it was great to catch it in flower.
At another site nearby, we caught some late flowering plants of Asclepias tuberosa var. rolfsii.
We visited several patches of amazing pitcher plants, one site with a tremendous variation of Sarracenia flava, which is typically solid yellow. Other sties had three species growing side by side including Sarracenia minor, Sarracenia rubra, and Sarracenia flava. It’s great that such natural area still exist, although they are always in danger from those who sadly dig plants from the wild for sale.
A plant often seen near the pitcher plants is the native orchid, Plantanthera ciliaris.
We were thrilled to find a couple of large patches of the scrub palm, Serenoa repens, from one of the coldest natural populations, which happened to be in full seed. Clonal patches like this are incredibly slow-growing. Researchers in Florida found that such clonal patches are often between 5,000 and 10,000 years old.
It was great to see large drifts of one of our finest native ferns, Thelypteris kunthii, aka: maiden fern. This superb deciduous fern thrives in both sun and shade, tolerating everything from wet to average soil conditions.
A lovely surprise was stumbling on a population of Hamamelis henryi. This coastal species is often listed as a variety of Hamamelis virginiana, but we think it’s probably deserving of species status. Several of the clones we found had lovely dusty blue foliage.
One of the most amazing shrubs was the hawthorn, Crategus munda var. pexa. These ancient specimens topped out at 4-5′ tall, and looked like ancient bonsai specimens.
I’ve long had a penchant for finding gold leaf sweet gums, and this trip added another one to the list. When many woody plants are cut to the ground, they are much more likely to produce mutations as they re-sprout. In my experience, the genus Liquidambar must be the most prone to such mutations.
The fall-flowering Georgia savory, Clinopodium georgianum was in full flower. We’ve grown and offered this for decades, but it was fascinating to see the flower color variation in the wild.
At one stop, we found five different liatris species, including the little-known Liatris elegans.
The native vining legume, Centrosema virginiana, aka: butterfly pea, was in full flower and looking lovely…first cousin to the better known genus, Clitoria.
I’m not a fan of most smilax species, but I was quite smitten by the non-running dwarf Smilax pumila, which grew in the shade like an Asarum (wild ginger). While some clones had green leaves, others had patterns every bit as good as the best Asarum.
On the ride home, we kept ourselves amused unscientifically researching the fastest speed at which leaf-footed bugs could hold onto a car window while copulating. Since our test speed topped out at 65mph, we aren’t sure what it was take to pry these loose, but perhaps someone should research how they are able to hold on so tight, as I’m sure it has numerous industrial applications.
We always look forward to elephant ear evaluation day at JLBG, which was recently completed.
Each year, Colocasia breeder, Dr. John Cho flies in from Hawaii to study and select from our field trials of his new hybrids. This year we were joined by Robert Bett, owner of the California-based plant marketing firm, PlantHaven, who handles the Royal Hawaiian elephant ear program. The JLBG trials consist of all named colocasia introductions growing alongside Dr. Cho’s new hybrids created the year prior.
JLBG staff members, Jeremy Schmidt and Zac Hill spent most of the morning working with Robert and John on the time-consuming evaluation process.