Tuff Tuft

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.

Ophiopogon japonicus ‘Tuff Tuft Lavender’

Holiday Cast Offs

During the holidays, house plants often get relegated to dark, unattended corners, but some house plants make great holiday decorations without any special seasonal input. One of those is the Taiwan native cast iron plant, Aspidistra attenuata. Here are 3 clones in our collection, all photographed this year on Christmas day. In order, they are Aspidistra attenuata ‘Alishan Broad’, ‘Dungpu Dazzler’, and ‘Taiwan Treasure’. These are but a few of the amazing cast iron plant species and cultivars that are sadly ignored commercially. We think they’re pretty cool.

Image of Aspidistra attenuata 'Alishan Broad'
Aspidistra attenuata ‘Alishan Broad’
Image of Aspidistra attenuata 'Dungpu Dazzler'
Aspidistra attenuata ‘Dungpu Dazzler’
Image of Aspidistra attenuata 'Taiwan Treasure'
Aspidistra attenuata ‘Taiwan Treasure’

Genetics Matter

We have long been enamored by the elegant, evergreen fern, Polystichum neolobatum, but have failed countless times with the commonly sold material in the horticultural trade. It was not until we grew spores from a Hans Hansen Chinese collection from 7,000′ elevation in China’s Sichuan province that we met with success. Below is a specimen from that trip, taken here at JLBG last week.

As is the case with so many commercially sold plants, their origin is lost. While the commercial material of Polystichum neolobatum may be fine in the cool temperatures of the Pacific Northwest, that is simply not the case here in the hot, humid Southeastern US. This species has a wide native range from the Himalayas all the way to Taiwan, where it can be found from 4,000′ elevation to 10,000′ elevation. Both elevation and origin location matter when determining the adaptability of many plants. We are finally getting good spore set, and hope to be able to make this form available through Plant Delights in the near future.

Polystichum neolobatum ‘YuWa’

Pregnant Rohdeas

This is a very good year for the annual winter fruit show on Rohdea japonica (sacred lily). The attractive berries remain until early March, when they begin to drop. Although seed from these cultivars do not come true, you’ll always end up with an interesting variety of offspring.

Rohdea japonica ‘Get in Line’
Rohdea japonica ‘Shichi Henge’
Rohdea japonica ‘Golden Eggs’

Dry-opteris on a Wet, Rainy Day – New Relevations

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.

Dryopteris bissetiana comparison

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.’

Dryopteris bissetiana commercial clone
Dryopteris bissetiana CSC009008 (Darrell Probst collection)

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.

Dryopteris formosana forms

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.

Dryopteris formosana comparison diploid left triploid right

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).

Dryopteris formosana triploid

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

Literature cited:

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.

Fall-flowering hemiboea

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.

Hemiboea strigosa blooming in the garden.
Hemiboea strigosa

You’re so Vein…Anastomosing, that is

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.

Coniogramme japonica - spore pattern on leaf back
Coniogramme japonica – spore pattern on leaf back
Close up of Coniogramme japonica showing anastomosing veins
Coniogramme japonica – spore pattern close up

Jurrasic Fern

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.

Pronephrium penangianum 'Jurassic Park'
Pronephrium penangianum ‘Jurassic Park’

Mahonia nitens

If you think you know mahonias, then check out this little-known species, flowering now at JLBG. Mahonia nitens is endemic to Guizhou and Sichuan, China. This is a form selected by Japanese plant explorer, Mikinori Ogisu. For us, the plant matures our at 4′ tall x 5′ wide, with flowers that appear orange, due to the color of the flower buds. Hardiness is unknown north of Zone 7b.

Mahonia nitens
Mahonia nitens

Pinto – A Subcompact Love Lily

One of our favorite love lilies in our 2003 introduction, Amorphophallus konjac ‘Pinto’. This amazing dwarf never has foliage that exceeds 16″ in height. Unfortunately, the ridiculously slow growth rate has kept us from offering it again since, but perhaps one day. Here is our parent plant in the garden this week. Even if you don’t have a home garden, this form is superb in a container. We had a large crop of dwarfs from seed two years ago, and are looking for more unique new compact selections.

The Cobras of Summer

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.

Arisaema candidissimum
Arisaema franchetianum
Arisaema purpureogaleatum

David’s Tree

We’ll certainly remember 2022 for many reasons, but a highlight is the first flowering of our Davidia involucrata ‘Sonoma’. This incredible tree was named for French missionary and naturalist, Armand “Pere” David (1826-1900), who first discovered the tree in its native China.

Like dogwoods, what we think of as flowers are actually bracts, the effect is that of the tree in flower is like a dogwood on steroids. Interesting, davidia is in the black gum family, Nyssaceae, and although this tree is not common, it has acquired the common name of dove tree.

We’ve learned a bit about what davidia likes, having killed five plants since first trying it in 2002. Full sun is not ideal, as is deep shade. Our original plant, which as been in the ground since 2002 has yet to flower. The plant of Davidia ‘Sonoma’, which flowered this year, was planted in 2014, and is thriving in light shade/part sun.

The Seals of Solomon

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.

Polygonatum mengtzense BSWJ11691

The dwarf, glossy-leaf Chinese Polygonatum nodosum just oozes elegance.

Polygonatum nodosum

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’

Polygantum x marcatum ‘Wisome 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 ‘Chanticleer’

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.

Polygonatum odoratum ‘Angel Wings’ (aka: Carlisle)

A Little White Lying Groundcover

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.

Mukdenia – a Rocky Sax

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)

Mukdenia in situ, Mt. Sorak, Korea

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.

Mukdenia rossii ‘Karasuba’ in crevice garden – late March
Mukdenia rossii ‘Karasuba’ in crevice garden – early April

Sweet as Snow Cream

Edgeworthia chrysantha ‘Snow Cream’ is a 2000 Juniper Level Botanic Garden/Plant Delights introduction that has proven to be one of our most popular introductions. We made the original selection from a group of seed-grown plants, imported from China by Canada’s Piroche Plants in the late 1990s. We were drawn to this seedling because of the particularly large flowers, and large leaves that reminded us of a plumeria. Let me be clear that all Edgeworthia chrysantha seedlings are nice, but there is certainly a significant difference between flower and leaf sizes of seed-grown plants.

Below are photos from our winter open nursery and garden days this year, where our garden specimens never cease to amaze visitors with both its sweetly scented flowers and amazing floral show. Sadly, no matter how many we propagate, it never seems to be enough to meet the demand. A more open site results in a much better floral show. Hardiness is Zone 7a – 10b.

Ginger drama in the Garden

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.