It’s been quite a floral extravaganza this spring in the dryland garden sections. Here are the latest of our flowering barrel cactus that have bloomed recently at JLBG. All of our cactus are growing outside without any winter protection in our zone 7b garden. The key for most is simply good soil drainage.
Delosperma cooperi and Delosperma ‘Kelaidis’ have formed a lovely union in our crevice garden, where they grow in pure Permatill gravel. The key to growing ice plants in a hot, humid, rainy climate is excellent drainage.
Looking great in the crevice garden this month is the Pacific Northwest native, Dichelostemma ida-maia This odd little bulb is a member of the Asparagus family…so that makes it as cousin to agaves, hostas, and asparagus. In the wild, it is only found in coastal meadows and into forest edges and partial woodland openings in Northern California and Southern Oregon. As a rule, California natives typically aren’t climatically welcomed in the rainy Southeast US, but Dichelostemma ida-maia is an exception.
Clematis vinacea is a recently described species of non-vining clematis, published in 2013 by plantsman Aaron Floden. In the wild, it grows in a small region on the border of Eastern Tennessee/Northern Georgia. Closely allied to Clematis viorna/Clematis crispa, Clematis vinacea is a compact, non-climbing species. For us, it makes a sprawling mound to 18″ tall x 4′ wide that flowers from May through summer. In habitat, Clematis vinacea prefers a dry, alkaline site, but it has shown good adaptability to slightly acidic soils in our trials.
The Greek bellflower, Campanula formanekiana has been superb in the crevice garden this spring. This amazing monocarpic (dies after flowering) species take three years to flower, and when it does, it puts on one heck of show. It’s namesake was Czech botanist, Eduard Formanek (1845-1900). We’re hoping for a good seed set. Hardiness is Zone 7a-9a, at least.
Nierembergia ‘Starry Eyes’ is looking particularly dazzling in the rock garden at JLBG. Starting to flower for us in late April, this incredible gem is from our 2002 botanical expedition to Argentina. I distinctly remember walking by as our friends from Yucca Do Nursery extracted a small piece of this nierembergia with only a single flower attached. I remember thinking to myself how poorly nierembergias, in particular Nierembergia repens perform in our climate and how I wouldn’t have wasted my time on such a plant. Two decades later, boy was I wrong!
In our climate, Nierembergia gracillis ‘Starry Eyes’ blooms continually through the summer months. It thrives in full sun and a well drained, gravelly soil. Thank you Yucca Do, for all the great introductions!
The crevice garden has “woke” for spring, with early flowering plants in full gear. Here’s a shot of one small section, featuring Delospema dyeri and Iberis simplex (taurica). We hope you can visit in person for the second weekend of our spring open house, May 6 – 8, 2022.
Spring is unquestionable peak cactus flowering season at JLBG. Although many of you are familiar with our large opuntia (prickly pear) collection, we thought we’d focus on the more diminutive barrel cactus, which you will see if you visit during our spring open house. Keep in mind that most close at night, not reopening until 10am-noon the following day. The photos below are just a tiny sample of the cacti that will be in flower.
I fell in love with puccoons several decades ago, when I first saw them growing on the Michigan dunes as I hiked around the shoreline. I was immediately smitten with this native member of the Borage (pulmonaria) family. There are 21 different species of Lithospermum (puccoon) in the US, where some go by the common name, stoneseeds.
It would take me five transplant attempts over the next three decades before we were able to successfully get one established in the garden. The photo below is our collection of Lithospermum caroliniense (hairy puccoon) from East Texas, flowering now in it’s new home adjacent to our crevice garden. This species is partial to acidic, sandy soils, so our next task is to figure out what other conditions it will tolerate and then to get it propagated, so we can share.
Ok…raise your hand if you’ve grown Aphyllanthes monspeliensis? This odd, monotypic (only member of the genus) is actually a member of the Asparagus family. Hailing from France south into Northern Africa, Aphyllanthes can be found growing in hot, dry, sandy soils, where it produces an amazing spring show of blue flowers on a 1′ tall clumper. The species name “monspeliensis” is named after Montpellier, France, where it grows naturally. Our plants are thriving in our crevice garden, putting on a superb flower show in mid-April.
Will someone please explain to me why more people aren’t growing the amazing sea kale, Crambe maritima. This amazing perennial is a great tasting green that returns every year without replanting. It’s also a great flowering perennial, putting on a show now in our rock garden. We have also never seen any pest activity such as typically bothers other members of the cabbage family. Our plant is growing in half-day sun in pure gravel (in our crevice garden), and never receives any supplement irrigation. The economic return from Crambe maritima is huge. I guess some folks may not find it attractive, but darn, folks!
Mukdenia is an odd monotypic genus in the widespread Saxifrage family, along with cousins heuchera, tiarella, and the namesake saxifraga. The odd genus name honors the former city of Mukden in Manchuria, which is now known as Shenyang. Mukden was the site of the largest modern day battle, prior to WWI. In case you missed it, the final score was Japan 1, Russia 0.
Several on-line sites, including that purveyor of accuracy, Wikipedia, proclaims there to be two species of Mukdenia, which is sadly incorrect. Although I’m sure Mukdenia rossii would like a sibling, one simply does not exist. I think of Mukdenia like Smucker’s…with a name like that, it has to be good…and it is.
Mukdenia naturally resides in China and Korea, where it can be found in some rather inhospitable places. I had to laugh when I read countless on-line articles that repeat the myth that mukdenia needs water during summer drought. It certainly doesn’t mind summer water, and will probably look better as a garden specimen with some irrigation. My first encounter with mukdenia in the wild was in fall 1997 on South Korea’s Mt. Sorak, where it thrived, growing in the rock cracks of a nearly vertical cliff (below)
When we built our concrete crevice garden, mukdenia was one of the first plants I wanted to plant to see if it would mimic what I had seen in the wild. Below is our 2017 planting of Mukdenia rossii ‘Karasuba’ in late March/early April 2022, as it emerges in flower. The foliage continues to expand around the flowers. Our plants get 3-4 hours of sun each morning, then shade the remainder of the day. Winter hardiness is Zone 4a-7b.
The South African (Eastern Cape) Bergeranthus vespertinus has been absolutely fabulous this late winter/spring season. Here it is growing in one of our rock gardens, where it is mostly protected from winter moisture. (Hardiness Zone 7b and warmer…at least)
Not only did we have 100% survival on our living stones (Lithops aucampiae ssp. koelemanii) in the garden, despite low temperatures of 15-16 degrees F, but they are now in the process of splitting, which is sort of like giving live birth. Splitting happens after flowering, and followed by a subsequent dormancy. The plant divides and the new plants absorb the of the old foliage…sort of like The Blob movie. We were fortunate to catch the process visually for the first time this week.
My visit to Crete in 2010 was eye-opening when I observed that most native daphnes of the region grew in full sun among rock, in the driest conditions imaginable. That prompted us to re-try many of the daphnes that we’d killed years earlier…obviously, with too much kindness. Now, all of our daphnes are planted in baking sun in our crevice garden, or similar rock garden conditions. Here are a few photos at JLBG from early April.
The first is the Mediterranean native, Daphne collina, which most authorities now subsume under Daphne sericea. All daphne pictured below should be hardy from Zone 6a – 8b.
Daphne ‘Rosy Wave’ is a Daphne collina hybrid with Daphne burkwoodii
Daphne x napolitana ‘Bramdream’ is a hybrid of Daphne collina and Daphne cneorum.
Flowering now in the rock garden is the European native, Anthyllis coccinea…aka: red kidney vetch. This small rock garden legume (Fabaceae) is still in its first full year in the ground, having been planted last June…so far, so good.
Antennaria solitaria, the solitary pussytoes is looking great in the garden this week. This amazing native groundcover hails from Ohio south to Alabama, where it can be found in open shade or part sun, but always in dry soils. Despite being native in acidic soils, our plants below are thriving in our alkaline crevice garden.
Wednesday, March 23, 2022 is the NC State University Day of Giving…a time for those who want to support activities at NC State. In our case, that means the endowment we are building to preserve Juniper Level Botanic Gardens. If you care about ensuring the gardens remain intact for future generations, please consider making a contribution to the endowment. You can do so at this link to the University Endowment Fund for JLBG.
For those who are relatively new to the gardens, here is a link to a historical timeline of the JLBG garden development.
You can find out more about the mission and future of the gardens here
Most hardy cactus have the good sense to wait until spring to flower, but not Notocactus haselbergii. This gem, which hails from Southern Brazil, started to bloom the first of March, and will continue on and off most of the summer. It has thrived for several years in our crevice garden.
One of our winter garden favorites is looking so good right now, that we had to share. Oxalis palmifrons is an amazing, but slow-growing rock garden gem, that hails from the South African karoo. We offered this through Plant Delights almost a decade ago, and it will be some time before we have enough to offer again.
We have long loved small crevice-sized succulents, but have also killed far more than our share, due mostly to our wet, cold winters. The newest star in our trials is the South African, Rabiea albipuncta, a first cousin to the better known, Delosperma. We should mention, that new DNA research has actually suggested a name change to Nananthus vittatus would be more correct, so we’ll be re-tagging shortly.
This gift from Denver Botanic Garden plantsman extraordinaire, Panayoti Kelaidis, has thrived in the gardens since 2018. We actually tried this back in 2004, but our site simply didn’t drain well enough in winter. This image was taken here at JLBG on February 2 this year, which shows how insanely tolerant the flowers are of cold weather. We hope to make this available next year through Plant Delights Nursery. This gem forms a substantial caudex, and as such is highly prized by bonsai enthusiasts.
Since ferns are one of the groups on which we focus our ex-situ conservation efforts, we have collected a huge number of species and selections from around the world. One that has continually frustrated us is the miniature rock fern, Asplenium trichomanes. Although this small gem is native to every continent except Antartica, we have struggled to keep it alive.
In our travels, we have collected it from Europe to Africa, but have also managed to kill all of those collections in the garden. Since our first attempt in 2004, we have now killed Asplenium trichomanes 16 times. We believe, however, in the late JC Raulston’s mantra, “Unless you are killing plants, you aren’t growing as a gardener.” The key is how many times do you continue to try before giving up?
We’re pretty stubborn as long as we feel we keep learning from each failure. Our latest accession of this species, which came as spores from Russia’s south coast, is actually thriving in our crevice garden, where the pH is north of 8.0. It seems that the crevice habitat is the answer.
Here is the reportedly tender Massonia depressa from South Africa in full flower in our crevice garden. I should add that this photo was taken 2 nights after we recorded 16 degrees F. I guess when the source of all worthwhile information, Wikipedia, says “When cultivated in a temperate environment, M. depressa does not tolerate freezing temperatures, so must be grown under glass in a cold greenhouse or similar.” we should take that as fake gardening news. Hmmm.
Massonia is a genus of bulbs in the Asparagus family, related to the more familiar genus scilla. Winter hardiness of this species is….well, still to be determined, but we’re good to at least Zone 8b so far.
Most plants have Latin name epithets (the 2nd word) that describes/commemorates either a place, person, or plant characteristic. In this case, the foliage of this Greek wooly mullein (Verbascum undulatum) is ridiculously wavy. Here it is looking great in our rock garden during the early winter. This will be our first full winter with it in the ground, so fingers crossed that it survives.
We’ve been experimenting to see how many species of asclepias will survive in our climate, and one that has been quite fascinating is Asclepias subulata. This odd species from the southwest deserts of the US has evergreen glaucous stems, and not much in the way of leaves. It will be quite interesting to see what the butterfly larvae actually consume. It did flower for us this fall for the first time. This will be our first winter, so fingers crossed it can take our cold and wet temperatures. We sited this on a slope in one of our crevice gardens, so it wouldn’t drown in our summer rains.
Looking particularly good this week is one of the Southeast US (NC to Texas) native water orchids, Habenaria repens. This gem flowers through most of the growing season, and hasn’t slowed down as we enter November. Water spider orchid can grow both as a marginal or as a true aquatic. Our plant is growing in one of our crevice garden seeps. We’re working to get this really cool native propagated and available in the future.
We’ve tried growing living stones (Lithops) a few times over the last decade in the garden, but could never get them to last longer than a couple of years. We weren’t loosing them to cold temperatures, but to moisture. So, when we built the crevice garden, lithops were one of the first plants we wanted to try again. We designed the crevices with overhangs to keep water completely off certain special plants, and that’s where we planted our seed-grown living stones.
For those who haven’t grown these irresistible gems, Lithops are South African succulents in the Azoiceae family, native to very dry and mostly tropical regions. They are prized for their odd appearance that consists of only two camouflouged succulent leaves.
We’ve never been able to coax a lithops to flower until last week. In their new crevice home, several finally decided to bloom this fall, with a sucession of flowers that still continues. We are currently growing only one species, Lithops aucampiae, but now that we’ve been successful, we’ve planted seed of more species to try. It takes us about 18 months from seed to get a plant large enough to go into the garden.
Despite everything written about lithops being tropical, we have not found this to be the case. Like so many plants, not enough people have been willing to experiment in colder climates in the right conditions. Of course, if you believe everything written on line, you’ll know for sure that they can’t take anything below 40 degrees F. Hint…ours have made it fine in the garden to 13F, so we expect them to tolerate even colder temperatures if kept dry. Wish us luck and be sure to check out the stones growing in the crevice during our next open house.
As an avid bromeliad collector back in the 1970s, I’ve had a long fascination with members of the bromeliad family. Although, I’m long past my house plant days, I continue to test bromeliads from cold climates for their adaptability in our Zone 7b NC garden. So far, we’ve had one member of the genus Puya to survive for well over a decade, so we’re trying more. Here is our trial clump of Puya caerulea var. violacea this week, where it is thriving so far in the crevice garden. This 2.5 year old plant is just waiting for a really cold winter to see how it fares, but so far, so good.
One of our favorite of the US native (Central Texas) desert ferns is Pellaea ovata. Here is our clump in the crevice garden looking quite nice this week. This is scheduled to return to the Plant Delights catalog in January. Hardiness should be at least Zone 7b and south.
Try as we might, we have been epic failures trying to grow the showy southwest native Zauschneria (now epilobium) in our garden, due to the combination of high humidity and torrential summer rainfalls. No matter where we tried them in the rock garden, they quickly expired. That was in the years BC…before crevice. Here is our plant of Zauschneria canum var. arizonica ‘Sky Island Orange’, a David Salman selection, planted in early 2018 and still thriving in our urbanite crevice garden. Not bad for a plant that doesn’t grow here.
We admit to a long-standing case of buckwheat envy. Every visit to the worlds great rock gardens, such as the Denver Botanic Garden, leave us lusting to grow the rock garden genus, eriogonum. We’ve killed many members of the genus, since they truly hate our humid and wet summers. Even our crevice garden was no help in keeping these alive, even including our reportedly easy-to-grow Appalachian native, Eriogonum allenii. After almost giving up several times, we can finally declare success with the Texas native Eriogonum longifolium, from our East Texas botanizing expedition. Here’s our clump in full flower, and quite happy in one of the rock garden sections. Granted, it’s not as stunning as some of the species that thrive in Denver, but hey, we can now check that genus off the list.
Looking good this week is Nierembergia ‘Starry Eyes’. We have special memories watching our friend Carl Schoenfeld collect cuttings of this on our 2002 botanizing trip to Argentina. While it’s only reliably winter hardy to Zone 8, it’s a flowering machine during the summer. Here it is growing in our new crevice planting near our Open House welcome tent.
After a long spring/early summer flowering season, we’re now enjoying the seed head of Clematis hexapetala ‘Mongolian Snowflakes’. Here it is growing in our fully sun, gravelly crevice garden.
Our patch of Aloe cooperi has been beautiful in flower this summer, but every time I see it, my mind automatically associates it with rocker, Alice Cooper. I guess he made quite an impression on me as a child. Aloe cooperi is the hardiest of the aloes, first cousin to the better known Aloe vera. Aloe cooperi has been fine here in Zone 7b for decades, but we doubt it would be winter hardy much further north.
Most keen botanist are familiar with the late French botanist, Andre’ Michaux (1746-1802). Michaux was a pioneer in botanizing North America, but how many people have actually grown the plant genus named in his honor. Michauxia is a genus of seven species, sister to campanulas, that hail from the Mediterranean though much of the Middle-East. We are fortunate to have his namesake, Michauxia campanuloides in flower this week for the first time, where it is thriving in the crevice garden.
To identify plants that are new to us, we start with the time-tested step of determining how close plants look to relatives we already know. This comes first, before we dive into floral dissection, etc. In most cases, we can get pretty close to a correct id, since we’ve grown and seen such a large number of plants. Two plants that threw us completely off the trail when we first saw them, are flowering now in the crevice garden here at JLBG.
The first, below, is Digitalis obscura, the Spanish Foxglove. I’d have lost big had I wagered on its identity when I first saw this, since I would have bet the farm that it was a penstemon, since the flowers and foliage share such an amazing resemblance to that genus. It’s taken us years to find a spot well-drained enough for this to survive in our rainy, humid, climate, but the wait was worth it.
The second plant that doesn’t seem to fit its genus is also flowering now in the crevice garden…Penstemon ambiguous. This Southwest/Great Basin native, known as sand beardtongue, looks nothing like other members of the penstemon family, which are usually easily recognizable at first glance. Instead, it could easily be mistaken for a phlox. This is our third year for this gem, so perhaps this may appear in our nursery offerings one day.
Most people are in too much of a hurry when they visit gardens and subsequently miss so many of the tiny gems in the garden. Here our clump of the South African native Ledebouria inquinata that was in full flower in the crevice garden during our recent spring open house. I wonder how many people actually walked slow enough to notice this tiny gem and its massive floral show. How about a “slow gardening” movement?
Allium ‘Ostara’ is a new bulbous ornamental onion from a cross of the lovely, but difficult to grow (in the southeast US) Allium karataviense and Allium atropurpureum. We’re growing this in our crevice garden, which is working well…so far. We’re hoping the genes from Allium atropurpureum will make this more growable.
Blooming now in the crevice garden is one of our favorite edimentals. If you haven’t heard this word before, it’s the new combo term for edible ornamentals. Crambe maritima, known as sea kale, is a plant we first grew for its fragrant flowers, only to find it incredibly tasty, both fresh and cooked. We are constantly grabbing a leaf for a garden snack. Best of all, Crambe maritima is a perennial that doesn’t need to replanted yearly. We can’t imagine why every lover of kale doesn’t grow this. Dry full baking sun is all that’s required.
Looking truly superb this spring is the South African ice plant, Delosperma dyeri in the crevice garden. We can’t grow this in typical soil due to our high rainfall, but in our crevice garden where gravel is the main planting media, it performs like a champ.
While daphnes have a reputation for being tough to grow, many are actually quite easy if given proper siting. My life with daphnes changed significantly after my 2010 botanical expedition to Crete. I was shocked to find daphnes growing in full baking sun in bone dry regions among large rocks. Before then, I had obviously taken far too good care of my daphnes. Once we constructed the crevice gardens at JLBG, we replaced all the daphnes we’d killed in “better” garden locations. Here’s the Cretan native Daphne sericea in full flower.
When we finally discovered that sea kale (Crambe maritima) is indeed growable in our hot, humid climate, we’ve planted it all around. It’s also been rewarding that people have actually purchased it to try for themselves. Frankly, I’d grow sea kale for the ornamental value alone…a perennial with blue waxy foliage and an incredible show of white flowers in spring! Then, there’s the edibility, both cooked and raw. Also, for us, unlike other cabbages and kale, it has been virtually untouched by the pesky cabbage loopers.
Here is a photo of sea kale in our crevice garden this April, growing in a soil mix that’s 50% gravel, with no summer irrigation. Read my lips, I mean text…full baking sun and no irrigation after establishment. We recommend you never let your plants read the repetitive on-line sites that all tout that it only grows in cool, moist, climates…hooey!
Unless you’ve been hiding under a piece of concrete, you’ve no doubt heard of our crevice garden experiment, constructed with recycled concrete and plants planted in chipped slate (Permatill). It’s been just over three years since we started the project and just over a year since its completion. In all, the crevice garden spans 300′ linear feet and is built with 200 tons of recycled concrete. The garden has allowed us to grow a range of dryland (6-12″ of rain annually) plants that would otherwise be ungrowable in our climate which averages 45″ of rain annually.
One of many plants we’d killed several times ptc (prior to crevice) are the arilbred iris, known to iris folks as ab’s. These amazing hybrids are crosses between the dazzling middleastern desert species and bearded hybrids. Being ready to try again post crevice (pc), we sent in our order to a California iris breeder, who promptly emailed to tell us that he would not sell them to us because they were ungrowable here. It took some persuading before they agreed to send our order, but on arrival, they became some of the first plants to find a home in the new crevices. Although we’ve added more ab’s each year, the original plantings will be three years old in August. Here are a few flowers from this week.
Iris are just a few of the gems that can be found in our “cracks”, continuing below with dianthus. As we continually take note of our trial successes, more and more of those gems will find their way into our catalog and on-line offerings…as long as we can produce it in a container. Please let us know if any of these strikes your fancy.
If that’s not enough, here are some more shinning stars currently in bloom.
If any of this seems interesting, you probably should be a member of the North American Rock Garden Society…a group of similarly afflicted individuals. If you are specifically addicted to cracks, check out the nearly 2000 strong, really sick folks on Modern Crevice Gardens on Facebook
When we completed our crevice garden, we wanted to see if it would be a good home to cyclamen, since they like to grow naturally in well drained sites, and sites that are very dry during their late spring/early dormant period. Here, they also get a couple of hours of morning sun, but shade after that and no supplemental water. The soil mix is about 50% Permatill and 50% native soil/compost. Here are some photos recently taken this winter showing how they have fared. The joy of growing cyclamen is that each seedling has a different leaf pattern…what amazing plants!
We’re now 2 years into our first successful attempt at growing the European Sea Kale, and have just finished our first flowering season. They key to success with Crambe maritima seems to be growing it hot and dry, since it resides in our gravel crevice garden. How cool is it to have a plants that is both ornamental and edible!
If you haven’t been out lately, the last section of our crevice garden along the exit drive is nearly finished and being planted as we speak.
Previous sections are starting to fill in nicely and really shining this spring. Be sure to visit during our upcoming 2019 Spring Open Nursery & Garden Days, May 3-5 & 10-12, and get inspiration for your own crevice or rock garden.
We have long admired the Aril iris, a group of dry-land species, mostly from Middle Eastern countries, which are renown for their ability to die quickly in wet, humid-summer climates. Well, armed with our new crevice garden, we decided it was time to try our hand at these once more, focusing on what is known as Arilbred iris…aril species that have been crossed with more typical bearded iris. In our case, we focused on the 50/50 hybrids, which the vendor assured us would not have any chance in our climate.
Despite our wettest year on record, here we are, 20 months after planting without a single loss. Here are a couple of photos from last spring, as we await the 2019 show (two center photos) just a few weeks away. The crevice garden should look amazing for our Spring Open Nursery and Garden days…we hope you’ll come visit. The lesson…don’t believe anything you’re told unless you verify it yourself.
If you’re interested in learning more, visit our friends at the Aril Iris Society
This amazing list of plants, shared by members from around the world, is truly the place to find seed of rare, hard-to-find plants for rock gardens and pretty much any kind of garden. The seed list typically offers 3000-4000 different plants annually…probably the best in the world. The first round of distribution in January of each year is limited to 25 different seed types (35 if you donate seed), and the second round, which just went live, allows members to select another 100 varieties. We just got out order submitted, and now anxiously await their arrival.
We think the seed exchange alone is worth far more than the annual dues, but there’s so much more from tours, to meetings, to networking, and a great journal. So, if you want to become a seedaholic, here’s your path to addiction!
In case you missed visiting us at our Winter Open Nursery and Garden, our spring event is coming soon…the first two weekends in May. Here are a few images of the garden in winter that you missed by not visiting!