Looking great for the last couple of weeks in the garden are the double forms of the Christmas rose, one of the first hellebores to bloom in the garden. This clump of Helleborus niger ‘Snowbells’ is looking particularly nice. Hardiness zone 3a to 7b.
Our 2nd earliest trillium is up and almost ready to flower. The deep south native Trillium underwoodii is the second toadshade to emerge, only behind the Florida genetics of Trillium maculatum, which emerges here in December. Although there is plenty of cold remaining, Trillium underwoodii is able to tolerate multiple nights of hard freezes below 20 F after the foliage has emerged. Winter hardiness is Zone 6a-9b.
Although the native Ostrich fern, Matteuccia struthiopteris ‘The King’, goes winter dormant, the fertile fronds remain upright and attractive all winter. Here, we have it growing among the evergreen Solomon’s Seal, Disporopsis pernyi. This site is quite dry, compared to it’s normal habitat of wet swamps.
We can’t imagine there are many people who grow cast iron plants from seed, but we have found the results quite fascinating. Below are a couple of our seedling which we found good enough to name. Neither has been divided yet, and are still under evaluation, but we think they have good potential.
Aspidistra ‘Bright Lights’ is a 2015 seedling from Aspidistra ‘Okame’ and has a similar variegation pattern, although it has more white banding than its parent.
Aspidistra ‘Illumination’ is a 2016 seedling of Aspidistra ‘Sekko Kan’, and inherited the white tips from its mama, but has also pickup up more streaking that wasn’t present in the preceding generation, so perhaps it outcrossed to a nearby streaked parent. If you’re interested in trying this yourself, the seed are found in a 1-2″ wide green ball at the base of the plant now. The seed should be mature in the next 4-6 weeks.
In 2014, Plant Delights introduced this amazing, wild collected mondo grass, which we think is one of the coolest ophiopgons we’ve ever grown. This Darrell Probst collection from China has formed a 20″ tall x 4′ wide mound of foliage. This image was taken in the garden this week after our 11 degree F freeze, and is looking absolutely fabulous. Although it keys out to Ophiopogon japonicus, it doesn’t phenotypically (what it looks like) that species. We’re pretty sure it represents a new undescribed species.
We love the texture, both in the woodland garden and in half day full sun. Although it’s winter hardy throughout Zone 6, it was one of the worst selling plants we ever offered. Sometimes we just want to throw our hands up trying to figure out why people don’t purchase some of these amazing plants.
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 – Dryopteris section 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.
Here are few images of our Solomon’s Seal (polygonatum) going to sleep in the garden. We think they are fascinating even as they approach dormancy. The top image is Polyongatum falcatum showing the amazing fruit set contrasting with the aging foliage.
The next image is Polygonatum odoratum, which probably has the best golden fall color of any species we’ve observed. At bottom is Polygonatum involucratum showing the transformation of the involucres (the pouches that hold the flower), and they age to tan, prior to the leaves changing colors. Solomon’s seal are cold hardy from zones 4 to 9.
We’ve published blogs about a number of carex from our rather large collection (108 species) several times this year, but here are a few more that look great here in early December. We have been fortunate to be able to collect members of this amazing genus from around the world, all of which now reside happily here at JLBG. As you can imagine, the majority of our collections are US native species, but just like with Homo sapiens, we value diversity and consequently don’t profile or discriminate based on ethnicity or origin.
The first is the US native Carex austrolucorum. This is Jeremy’s collection, named Carex ‘Tennessee Mop Top’.,
Carex gentilis ‘Yushan’ is our collection from Taiwan, and the only fall-flowering carex we know. Duke Gardens has made stunning use of this in their magnificent Asian garden expansion.
Carex ‘Silk Tassel’ is a stunning selection of the Japanese Carex morrowii var. temnolepis, brought to the US back in the 1970s by plantsman Barry Yinger. We still view this as one of the finest carex we’ve ever grown. While it grows great in shade, it truly excels in full sun, where its narrow variegated leaves appear silver.
Those old enough to remember the incessant Volkswagen commercials of the 1990s probably still can’t get the word Fahrvergnügen out of their brain. We’ve commandeered the term, which means “The Joy of Driving” to Farfugnügen…the joy of growing Farfugium.
We think more people should be growing this amazing genus of plants in the aster family. While most named selection are made for foliage only, with a less than stunning floral show, here is one of our favorite flowering selections, Farfugium ‘Jagged Edge’, that we’ll make available for the first time next year through Plant Delights. These fall-bloomers put on quite a show, which in most climates, ends with the first hard freeze. Hardiness zone 7b to 10b.
For several years, we’ve been fascinated with the genus, Hemiboea, a collection of 23 species of African Violet relatives, all native to China. We currently grow five of those, and two others that are still to be identified. On a 2020 trip to England, we picked up Hemiboea strigosa, which has been flowering beautifully here at JLBG, starting in early fall. The Latin word “strigosa” means stringy, which certainly describe the mat of stolons which lie right at the soil surface. So far, our plants have been through two winters, where they fared very well. If the good performance continues, we will start propagation soon.
Begonia U-521 is a species we got from a customer in Alabama, which has sailed through our winters at JLBG since 2017. Flowering begins for us in early fall, with clusters of large pure white flowers, which hide just below the leaves. For those unfamiliar with Begonia U-numbers, these are assigned by he American Begonia Society for plants new to cultivation that represent potential new species.
This amazing begonia was purchased by begoniaphiles Charles Jaros and Maxine Zinman from the Bangkok Market in Thailand. For those who haven’t visited this amazing marketplace, it’s a massive venue where local vendors (nurserymen and collectors) sell their wares.
It turns out that this species came from the wild via a collector who lives on the border of Thailand and Cambodia, where no plants should be winter hardy here in Zone 7b. We’re not aware of anyone currently working on naming new begonias from that region, so to offer it, we’ll need to assign a cultivar name, which will remain connected to the plant, once it becomes a published species.
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.
We love the winter hardy Chinese schefflera, Schefflera delavayi. This smaller and hardier version of the small tree that’s planted throughout central and southern Florida, is reliable for us here in Zone 7b. Here’s an image taken just prior to our first hard freeze. It’s been a few years since we got viable seed, so fingers crossed for this year.
Flowering now in the garden is the fabulous Fatsia japonica ‘Ripple Effect’. Although this isn’t currently on the market, we’re working diligently on propagation. Thanks to the US National Arboretum for sharing this amazing selection, which we hope to introduce in the next couple of years.
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.
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 Begonia with 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.
Dr. Patrick McMillan
The amazing Chinese native Pronephrium penangianum ‘Jurassic Park’ is looking fabulous in the garden this week. This large growing, spreading fern has the feeling of a plant from the time when dinosaurs roamed. We continue to make cool, but little-known ferns like this available to a wider audience. Hardiness is Zone 7b-9a at least.
We love the various shades of green displayed by the fascinating Fatsia japonica ‘Murakumo Nishiki’. This amazing Japanese selection of tree ivy is looking rather stunning in the garden this month. This is a slow-growing shrub, which should mature at 4′ tall x 6′ wide. There is a shortage of these in commerce currently, because of a problem with tissue culture lab production. Winter hardiness is Zone 7b-10b.
Looking good in the garden now is Begonia taiwaniana ‘Alishan Angel’, which is our 2008 collection from 6,500′ elevation in Taiwan’s Yushan Province. This specimen has now been in the ground since 2010, and is thriving in a fairly dry woodland location. We introduced this selection in 2020 and will be offering it again in 2023. Hardiness is Zone 7b-9b at least.
One of our favorite hardy garden ferns are the amazing cat’s claw ferns of the genus Onychium. The genus comprises between 9 and 23 species, depending on your choice of taxonomist.
The most common species in cultivation is the Japanese Cat’s claw fern, Onychium japonicum, which we’ve had the pleasure of offering many times through the year. Now, we’re working on getting another species into production, Onychium contiguum. Compared to Onychium japonicum, Onychium contiguum is much smaller and slower-growing with even finer cutleaf foliage. We picked up this Elizabeth Strangman wild collection during a 1994 trip to England’s former Washfield Nursery. Below is our original clump in the garden this week.
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.
Adiantum capillus-veneris ‘Bermuda Run’ is looking exceptional in the garden this fall. Actually, it looks exceptional most of the year for us. Until the temperatures drop below 12 degrees F, this amazing fern remains evergreen. This fern has a huge native range, being found on every continent except Antarctica.
Adiantum capillus-veneris, along with a couple of pteris fern species are often found growing in mortar cracks in many of the Southeast coastal cities and adjacent tropical islands. It is thought that some of these populations may have been spread along the early trade routes. This particularly dense form is our collection from the mortar walls on Bermuda. The same species is native to North Carolina, but only in a solitary population. Winter hardiness is Zone 7b-10b.
Raise your hand if you grow the woodland perennial, Collinsonia? These mostly fall-flowering, clumping perennials in the mint family (Lamiaceae) are wonderful elements for the woodland garden at a time when little else is flowering. Named by Linnaeus to honor English botanist Peter Collinson (1694–1768), the genus Collinsonia contains 11 species of which 4 are native to North America. Five species are native to China, 1 to Taiwan, and 1 to Japan. Pictured below in flower this week is Collinsonia punctata, which hails from South Carolina west to Louisiana. Winter hardiness is unknown, but we guess Zone 7a-9b, at least.
Looking particularly lovely in the garden is the elegant fern, Dryopteris affinis ssp. affinis. The semi-evergreen golden-scaled male fern from Europe is among the easiest and most beautiful ferns we grow, yet when we offer it through the nursery, it’s always one of the worst sellers. We struggle to figure out mysteries like this when you have a fern that grows equally as well in acid or alkaline soils, and grows the same in the Pacific Northwest as it does the hot, humid Southeast US. Winter hardiness is Zone 4a-8b.
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.
Looking particularly lovely in the late summer garden is Fatsia japonica ‘Murakumo Nishiki’. This irregularly gold variegated form of the typically solid green tree ivy is a star in the light shade garden. This evergreen gem is a great way to add a spot of color in the woodland garden year round. Hardiness is Zone 7b-10b.
I wonder if the late Atlanta nurseryman, W.L. Monroe had any idea what would become of his white-flowered monkey grass, that he selected as a seedling and subsequently introduced to the gardening world in 1957?
In the 65 years that’s passed since it’s introduction, Liriope muscari ‘Monroe White’ is still the gold standard by which all white-flowered liriope are judged. Here are our plants flowering this week at JLBG. Unlike most liriope, which thrive in sun, this cultivar needs light shade for most of the day to prevent foliar scorch. Our plants in the photo only get a couple of hours of direct sun, where they thrive. Winter hardiness is Zone 6a-10b.
I’m more and more impressed with Hosta ‘Miss America’ each year. Not only is this white-centered hosta amazingly vigorous, but it has one of the finest floral shows we’ve ever seen on a hosta. The steel rod-like upright flower stalks on our plant have reached 4′ tall, but as the plant grows larger, they will eventually top 6′ in height. Not wind, rain, or post office vehicle can knock down these super sturdy stalks, and the great show they provide for weeks. Our plant is 100′ from our back porch, and it shows up like a floral beacon even from that distance.
I’m always amazed that so many people don’t realize that turmeric (Curcuma longa) is an amazing garden perennial. We’ve had our plants in the garden for nearly 30 years. This week, the flowers of this delightful ginger lily from Southern India emerge, looking like fancy pink pine cones. Curcuma longa is very easy to grow, as long as the soil is reasonably well-drained. Just mark the planting spot, since it usually doesn’t break ground before June. Hardiness is Zone 7b-10.
Asparagus virgatus is undoubtedly one of our favorite textural perennials. How many evergreens do you know that thrive in shade with such an amazing texture, and can be cut for flower arrangements. If you’ve ever worked with cut flowers, you’ll recognize this as “filler” that you purchase with your flowers to add 3-D texture to your arrangements. Few people, however realize that it’s an easy-to-grow garden perennial.
Although in the wild, it grows along streams, it has proven to be one of the most drought tolerant plants we grow. In terms of light, an hour or two of morning sun is fine, but this South African asparagus species much prefers light shade all day. Unless winter temperatures drop below 10 degrees F, the amazing foliage stays evergreen. Hardiness is at least Zone 7b and warmer.
Plant nerds use the term BIO plant, short for Botanical Interest Only, for plants which have little, if any ornamental value, but are highly prized by crazed plant collectors. Spathicarpa hastifolia is such a plant. This odd aroid from Southern Brazil has actually thrived in our woodland garden since 2019. The coldest winter temperatures we’ve experienced in that period is 16 degrees F.
The small woodland plants mature at 1′ tall x 1′ wide, with oddly interesting flowers, which you can see in our image…if you squint. If this continues to perform well, and we can get it propagated, perhaps we’ll have some to share in the future. To quote our friend Bob McCartney, “We have the market cornered on plants for which there is no market.”
We recently ran across this clump of the summer-flowering native (Canada south to Florida) orchid, Goodyera pubescens growing in a site near JLBG. Like a century plant, the flowering rosette dies after flowering, but new side shoots are produced for future generations. Work is being done to produce this in tissue culture so it can be made more widely available from nursery propagated stock. Sadly, most plants sold today are wild collected.
Of the 100 species of Goodyera orchid, only 4 are US natives.
I can’t imagine a summer garden without the South African woodland bulb, Scadoxus multiflorus ssp. katherine. This amazing bulb in the Amaryllis family, grows best in light, open shade, where it bursts forth sans foliage in late June. This clump is right outside our kitchen window, making it hard not to smile. Hardiness is Zone7b and warmer.
While most arisaemas flower in early spring, several members of the Franchetiana section of the genus are summer bloomers. There are five species in this section, but the only one that flowers in spring is Arisaema fargesii. Flowering recently are those pictured below, A. candidissumum, Arisaema franchetianum, and Arisaema purpureogaleatum. The debate still rages on whether Arisaema purpureogaleatum is merely a form of Arisaema franchetianum, but regardless, it has a distinct appearance when in flower. Of these three, Arisaema candidissimum is the least tolerant of our summer heat.
Flowering this week is one of our favorite hippeastrum…what lay people call amaryllis. We think Hippeastrum ‘Germa’ is one of the finest yellow-flowered hybrids ever created for southern gardens. Sadly, this 1995 Len Doran hybrid (Hippeastrum parodii x aglaiae x evansiae) is rarely available any longer. We’ve had our garden specimen growing since 2000. Unlike many cultivars, Hippeastrum ‘Germa’ is a woodland plant.
One of the most Jurrasic-looking plants we grow is the North American native Ostrich fern. If you moved here from “up north” and brought some of this fern with you, chances are it failed miserably. As a rule, Ostrich fern, Matteuccia struthiopteris, hates our summer temperatures.
Fortunately, back in the mid-1980s, retired UNC-Charlotte botany professor, Larry Mellichamp picked up a heat tolerant form from Powell’s Nursery in Princeton, NC, which he promptly introduced into the trade as Matteuccia ‘The King’. Without this incredible introduction, gardens in south would not have this amazing fern in their gardens.
This is a spreading fern that prefers average to wet soils, so allow plenty of room for it to spread. Below is a patch thriving at JLBG.
We’ve just wrapped up the 2022 Southeastern Plant Symposium in Raleigh, and were thrilled to have nearly 200 attendees. It was great to be back in person after two years of remote Zooming. The symposium is co-sponsored by the JC Raulston Arboretum and Juniper Level Botanic Garden, with all proceeds split between the two institutions (JCRA operations and the JLBG endowment).
Attendees were entertained and enlightened by fourteen of the top horticultural authorities in the country/world. This years symposium was focused on perennials, 2023 will be focused on woody plants (trees/shrubs), and 2024 will focus on geophytes (bulbs, tubers, etc.) as part of our three year rotation.
We hope you’ll join us for 2023, and mark June 9, 10 on your calendar. Not only are the speakers excellent, but the symposium includes a rare plant auction, which this year, offered over 430 plants, most of which aren’t available anywhere else in the world.
One of our favorite ferns is the Lady fern hybrid, Athyrium ‘Ocean’s Fury’. Created in Pittsboro, NC by plantsman Thurman Maness, this patented gem was offered for years through wholesale channels, but sales were not strong enough, so the sole producer discontinued it. So often, great patented plants suddenly become unavailable if sales don’t warrant.
In Europe, any grower can petition the PVR office to request permission to propagate such protected plants, but no such program exists in the US. Fortunately, Thurman has generously granted us permission to propagate his amazing introduction and make it available. That said, division is a very slow way to make ferns available, but since this hybrid between Athyrium filix-femina and Athyrium nipponicum is sterile, it’s our only option.
Looking good in the garden this week is the amazing fern, Dryopteris x australis. This rare fern is a US native…despite the confusing name, hailing from only a few scattered locations from Virginia west to Arkansas. In reality, the name “australis” means from the south. This splendid specimen grows in both sun and shade, and tolerates both wet and dry soils. Hardiness is Zone 5a-9b.
We often talk about the amazing group of hardy asparagus ferns, so here we go again with a few that are looking particularly great now.
The first image is our dwarf selection of Asparagus cochinchinensis ‘So Fine’. This is our new dwarf selection from our original collection from Korea’s Mt. Chuwang. Hardiness is Zone 4b-8b, at least.
Asparagus tenuifolius ‘Vodice’ has proven to be an amazing garden specimen with a tight compact habit. This is our collection from Vodice, Croatia. It’s amazing that this incredible species is completely absent from gardens. We have no idea about winter hardiness, but would expect Zone 5/6 at least.
The amazing Asparagus sprengeri ‘Graham’s Cracker’ just continues to amaze us. This dwarf selection of the hanging basket asparagus fern from NC plantsman Graham Ray, has been reliable for years in Zone 5b, without the benefit of mulch or any other protection. We find it a superb textural contrast for bolder foliaged perennials.
Looking great in the JLBG gardens is the amazing Cyrtomium fortunei ‘China Ruffles’. This superb spore strain is from an original introduction by Michigan plantsman, Hans Hansen, who made the spore collection in 2003 in Sichuan, China. Hardiness is Zone 6-9.
Solomon’s Seals comprise several genera of woody perennials, but the common name is most commonly associated with the genus, Polygonatum in the Asparagus family. It seems hard to imagine, but the Asparagus family now includes many popular garden plants including its namesake Asaparagus, but also hosta, agave, liriope, ruscus, and yucca.
The genus Polygonatum is native through much of the world, although the center of distribution is in Asia. We’ve been collecting these amazing woodland perennials for years, and now have a collection of over 380 different taxa. Here are a few from this week in the garden.
Polygonatum mengtzense is a dwarf, rarely cultivated species from North Vietnam.
The dwarf, glossy-leaf Chinese Polygonatum nodosum just oozes elegance.
When you run out of species to grow, you start creating hybrids. This is our new selection of a cross of the giant Polygonatum martinii and the more compact, Polygonatum falcatum. We’ve named this clone Polygonatum x marcatum ‘Winsome Wonder’
Polygonatum odoratum ‘Chanticleer’ is a superb, large-leaf form of the Asian Polygonatum odoratum that I spied at Chanticleer Gardens, and they kindly shared in 2006. Hopefully, we’ll finally have enough to share next year.
Polygonatum odoratum ‘Angel Wings’ (aka: ‘Carlisle) is a superb form of Polygonatum odoratum from Massachusetts plantsman, Roy Herold. This gem grows in both half day sun as well as shade.
Over the last few weeks, I’ve been working on a plant survey of a local woodland area of about 30 acres. The low, moist areas are filled with Arisaema triphyllum, (Jack-in-the-pulpit) which is quite common in our area. The first image is what is typical for the species.
I’ve been studying patches of Jack-in-the-pulpit for well over 55 years, always looking for unusual leaf forms that showed any type of patterning. Until last month, I’d never found a single form with atypical foliage. That all changed with my first trip to this local site, where so far, I have found several dozen forms with silver leaf vein patterns. Up until now, there are only two pattern leaf forms of Arisaema triphyllum in cultivation, Arisaema ‘Mrs. French’ and Arisaema ‘Starburst’.
Each patterned leaf clone varies slightly as you would expect within a population including both green and purple stalk coloration.
While I’d never found any true variegation prior to this, I had found plenty of transient leaf patterning caused by Jack-in-the-pulpit rust (Uromyces ari triphylli). This site was no exception, with a number of plants showing the characteristic patterning. If you find these, turn the leaf upside down and you’ll see the small orange rust pustules.
While these may seem exciting, the pattern are not genetic and will disappear without the fungus. Fortunately, this rust can be cured by cutting off the top of the plant and discarding it where the spores can not spread via the wind. Infected plant should be fine, albeit smaller next year. The susceptibility of Arisaema triphyllum to jack-in-the-pulpit rust varies with genetics. Of the tens of thousands of plants I observed at the site, less than 10% were infected with the rust.
False lily-of-the-valley (Speirantha gardenii) is one of our favorite early spring-flowering evergreen groundcovers for shade, but one that just hasn’t caught on with customers. Every time we put this back in production at Plant Delights, we wind up throwing out most of the crop. Perhaps one day, folks will realize what a gem this is. Hardiness is Zone 5b-8b.
We are just starting with the first wave of Cypripedium (ladyslipper orchids) in the garden this week. One of the earliest selections to put on a show is Cypripedium ‘Rascal’, an outstanding cross of Cypripedium kentuckiense and Cypripedium parviflorum var. parviflorum…all US natives.
Arum are a fascinating genus of hardy aroids, known by most gardeners from a single southern European species, Arum italicum. The most popular cultivar of Arum italicum is Arum ‘Marmoratum’. The key to enjoying arums is to not let the seed drop everywhere, since you can get easily get over-arumed. Flowering season is now, followed by seed season. Each seedling has a different pattern from the original, so it’s a personal preference whether to remove seed or not.
Arum apulum is a little-know species that is rarely seen in cultivation, native only to a small region of Southern Italy. Our flowering plants in the garden now are from a wild collection made by a plant explorer friend.
Below is an interesting hybrid between Arum italicum (central to southern continental Europe) and Arum dioscorides (Mediterranean). Arum italicum has patterned leaves, but solid green flowers. Arum dioscoridis has solid green leaves and spotted flowers. The hybrid, Arum ‘Chui’ is an introduction from UK plantsman John Grimshaw. We added the notospecific (hybrid) name Arum x diotalicum. These hybrids have both spotted/speckled leaves and flowers.
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.
Here’s a fun combination this from the garden this week, where we combined two three-leafed plants together…a silver leaf Trillium cuneatum with the hardy purple-leaf shamrock, Oxalis triangularis. You can have all kind of fun making these little vignette combinations in your garden, using your school colors, or any other design scheme that suits your tastes.
If you’re a nursery, and you’d like to offer ferns, the plants at your disposal are somewhat limited. A large majority of ferns sold in America are still sadly dug from the wild. When you see a catalog listing primarily these ferns together…usually an very inexpensive prices, you can be pretty much assured they were dug from the wild: Osmunda regalis (royal fern), Osmunda cinnamomea (Cinnamon Fern), Polystichum acrostichoides (Christmas Fern), Matteuccia Matteuccia struthiopteris (Ostrich fern), Adiantum pedatum (Maidenhair fern), Athyrium filix-femina (lady fern), and Onoclea sensibilis (Sensitive Fern). These ferns are often sold bareroot, to save the nursery the expense of having to pot the collected plants, many of which are so large, they won’t fit in small containers.
The other majority of ferns in the market are produced by tissue culture, either by a couple of labs in Florida, one in Texas, and one in Holland. Without the amazing work of these labs, the fern selections available to homeowners would be limited to the wild collections. Even with their amazing work, these labs must focus on well-known ferns that sell in very large numbers.
While we make use of the lab offerings, we also made a commitment over 30 years ago to grow many of our own ferns from spores. Outside of a few small fern specialists, there are few nurseries who grow their own ferns from spores, since this is the most costly and time consuming option. The reason we do this is so that we can offer fern species and selected forms that are otherwise unavailable.
Below is a quick summary of how the process works. Fern spores (fern equivalents of seed) are collected through the summer, and are dried in paper envelopes until they separate from the foliage. They are then sown in pots with potting soil that is sterilized here, and then sealed in ziploc bags. The spore takes from 1 month to 6 months to germinate. Once the spores germinate, they are ready to have sex…a process that is reversed from more modern evolved flowering plants.
To assist the ferns have sex, we gently add water to the newly germinated sporelings, since ferns (other than desert ferns) only have sex while they are swimming. The water is swirled around to mimic the feel of a whirlpool, then the bags are then resealed, and put in the dark where they are subjected to a near constant montage of Barry White music.
Within a few weeks, tiny fern fronds begin to emerge. At this point, the ziploc bags are opened to allow the humidity to equalize with the ambient air. After another couple of weeks the pots are removed from the ziploc bags. If the spore were viable and cleaned well without contamination, and if germination was good, there will be up to several hundred plants per pot.
After a few weeks, the sporelings are transplanted into a cell pack flat. Here they grow out for another few months until they are ready to be planted into our 1 qt. pots, in which they will be sold. In all, it’s about an 18 month process, and a good bit of labor. We’re really quite passionate about our fern collection at JLBG, which the visiting British Fern Society declared one of the largest/most diverse in the world. We hope you find the results worthwhile.
We love all of our trout lilies, but Erythronium ‘Goldstrike’ is hard to beat. This is our named selection of Erythronium americanum ssp. harperi. Occurring from Tennessee south of Mississippi, this amazing form graces low woodlands in very early spring. This collection was made by our Plant records/taxonomist, Zac Hill in Alabama. Hardiness is Zone 6-9 at least.
Flowering at JLBG since early March is the little-known Jack-in-the-pulpit, Arisaema ilanense. This collection hails from Ilan (Yilan), in northeastern Taiwan, and for us is the very first arisaema to flower each winter, even when temperatures are still quite cold. The mature size is only 4-6″ in height, so this is one for a very special site in the rock garden. There are very few plants of this species in ex-situ conservation collections, so thanks to JCRA Director, Mark Weathington for sharing. Our specimen has been in the garden since 2016. Hardiness is unknown, but we’re guessing Zone 7b-9b.
Carex conica ‘Hime’ has been in horticultural commerce for many decades, and remains a superb woodland garden sedge. The evergreen species Carex conica is native throughout Japan, where it occurs in woodland conditions. This variegated selection that goes by an array of names such as ‘Snowline’ and ‘Marginata’, but Carex conica ‘Hime’, which translates to “princess” seems to the the correct cultivar name. The tight 10″ tall x 20″ wide clumps of narrow white-edged leaves are topped with this fascinating floral show for us in early March. In 35 years of growing this, we have yet to see a single garden seedling.
We’ve made a regular habit of killing fritillarias (the bulb…not the fried food) in the garden, especially those ungrowable brightly-colored species like Fritillaria imperialis that tantalizingly appear each fall in the major bulb catalogs.
Although it lacks the bling of it’s showier cousins, the species that is reliable for us in the garden is Fritillaria thunbergii. This native of Kazakhstan has naturalized in both western China and Japan, where it has been used medicinally for almost 1,000 years as a treatment for respiratory ills. There is still some debate among botanists whether some of the Chinese population might actually be native as well.
In the garden, Frittilaria thunbergii emerges in February, and is full flower at 2-3′ in height by early March. As with most spring ephemerals, it has gone to sleep by early May. Light shade or part sun seems to suit it fine. Hardiness is at least Zone 7a-8b.
One of the fun reasons to grow plants from seed is that each seedling is different…unless you’re growing highly bred annuals. Most non-hybrid seedlings will be under the bell curve, meaning they all look and behave relatively similar. As plant collectors, we get excited when one appears that falls outside the bell curve. An example is our wild ginger selection, Asarum maximum ‘Floragasma’, which has both far more flowers than we typically see with the species, but it also flowers 2-3 weeks before our other clones. Winter hardiness is Zone 7b-9b.
It was great during our recent winter open house to see so many folks noticing the aucubas in the garden. Of course, they are hard to miss with our collection of over 140 different taxa. There are few evergreen plants better for year-round interest in dry shade than aucuba. Here is one of the most fascinating ones that’s in flower now in early March, Aucuba himalaica var. dolichophylla. This little-known, narrow-leaf species hails from 3,000′ elevation in several southern Chinese provinces. Winter hardiness Zone 7a-9b, and perhaps a bit colder.
Trillium cuneatum ‘Oconee Gold’ is a rare gold-flowered selection of the typically purple-flowered southeastern toadshade. We found our original plant of this in Oconee County, SC, and have propagated them from seed since that time. If we keep the yellow-flowered plants isolated from purple-flowering clones, we have more than 50% that reproduce with yellow flowers. The time from seed to flower is usually five years. Winter hardiness is Zone 5a-8b.
A couple of weeks ago, we mentioned our landscaping project on the north side of Mt. Michelle to create more intricate planting pockets, while raising the planting heights significantly via the use of rock assisted berms.
Phase 2 of the project was to create a cut through on northwest side through a previously inaccessible bed. Phase 2 is now complete, and visitors can now traverse the new path, exiting into the northwest side of the Mt. Michelle waterfall. This path takes you under the large speckled-leaf loquat, Magnolia macclurei, and several large conifers, so be sure to look up as well as down.
Last week, Jeremy and his staff tackled phase 3 of the project, which was the two 50 degree slopes on the west side of Mt. Michelle. Despite being planted for some time, we had lost some soil due to runoff, and the plants were screaming for more compost, and we were screaming for more rock pockets.
In less than a week, Jeremy’s team stacked these new retaining planting walls, which provide hundreds of new planting pockets for small woodland treasures. Each is now filled with our garden compost mix as well as an array of small, little-known plants. Just remember, if you garden on flat ground and think you are out of planting space, the key is to learn to think like a Pythagorean…a² + b² = c²…go vertical.
You’ll be able to see these newly planted areas during our winter open house, although it will take a while for the plants to mature.
Flowering now in the woodland garden is this rad little windflower, Anemone raddeana. This Asian native (China, Japan, Korea, and Russia) is a plant you’ll almost never see for sale. First, it flowers in the middle of winter when few people are thinking about gardening. Secondly, it’s ridiculously small, producing only a single white flower per stalk, which rises only a couple of inches from a slowly creeping rhizome. Third, it’s a spring ephemeral, meaning it will be dormant by the first of May. Finally, most people move through life too fast to even notice little gems like this. That said, if you like things like this, this is exactly the kind of thing you’ll really like. We certainly do!
Few people know the fascinating native shrub, Dirca palustris. It’s little wonder it gets overshadowed by showier members of its family, Thymelaeaceae, which includes the likes of Daphne and Edgeworthia. Our 6′ tall plant is flowering alongside a large edgeworthia, and rarely gets noticed by visitors.
Dirca palustris, the plant, is actually widespread across Eastern North America, with a range from Canada to Florida, where it thrives in slightly moist, acidic soils. It’s often known as leatherwood, due to its thick, but very pliable branches, which have been used by Native Americans for making rope as well as baskets.
There are three other less poorly known dirca species…if that’s possible. We grow the rare Dirca decipiens from Kansas/Arkansas, but have not yet tried D. occidentalis from California, or D. mexicana from Mexico.
The genus takes its name from the Dirce in Greek Mythology, who bit the big one while tied to the horns of a bull….a truly sordid story. The specific epithet “palustris”, lacks the fascinating story of the genus, but only means that the plant naturally lives in very wet sites. Winter hardiness is Zone 3-9.
Here are a couple of images this week from the garden of our older clumps of Cyclamen hederifolium. For garden areas that are dark and dry, where nothing else grows, cyclamen are your best bet. Of the plants below, one is at the base of a cryptomeria and the other at the base of a pine. Although they flower from August until Christmas, the winter foliage is just hard to beat. Hardiness is Zone 4a-8b.
When people think of trilliums, they usually think of the cold north, but states like Florida are also home to four species of trilliums which all thrive throughout the southeastern states. Here are two of the earliest species to flower in our garden.
The first is Trillium maculatum ‘Kanapaha Giant’ from Alachua County. This is consistently the earliest trillium to emerge and flower for us. This is followed close behind by Trillium underwoodii. Both of these are usually in flower by early February.