Euonymus…a New Take

We were thrilled to see that our Euonymus myrianthus sailed through our recent cold snap. This fascinating species was first introduced to Western horticulture by renown plant explorer, Ernest Wilson in 1908, and has been quite slow to get around. Recent collections have finally made this available for trial in the US.

This small evergreen tree matures at 12-15′ tall, adorned with a show of bright orange fruit. We have tried a couple of collections, but this recent one from a Dan Hinkley, Ozzie Johnson, Scott McMahon collection is thriving for us. Hardiness is unsure, we we expect it will be fine from Zone 7a and south.

Image of  Euonymus myrianthus
Euonymus myrianthus

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’

Mr. Russell’s Mahonia

Mahonias have long been garden staples, but few people have ever seen or tried the rare Mahonia russellii. Discovered in 1984 in Vera Cruz, Mexico by the UK’s James Russell, this member of the “paniculate” clan of mahonias is more closely related to other Southern Mexico and Central American species, than anything most of us grow in our gardens. In other words, there is no way we should be able to grow this outdoors.

Below is our specimen flowering in the garden just prior to our low of 11 degrees F and three consecutive nights in the teens. Surprisingly, it escaped with what appears to be minor foliar damage, and of course a loss of the floral show.

Image of Mahonia russellii
Mahonia russellii

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’

Riverbank Sundrop; The Journey Begins

Great new plants for the garden do sometimes just happen. They can occur as a spontaneous sport from an existing planting, as a seed selection that has much better garden traits, but many of our most useful and ecologically important plants in the garden have their start in exploration. I was thinking about this today as I observed the tightly-clumping overwintering rosettes of one of our newest introductions to the JLBG—Oenothera riparia, Riverbank Sundrop.

Oenothera riparia basal clump in winter.
Oenothera riparia

Sundrops hold a special place in my heart. My grandmother loved them and had large swathes of the old pass along yellow standard Oenothera fruticosa/tetragona in her extensive garden. Every June they would burst into flower for a brief week or so, bringing a brilliant light and foil to her many glorious iris. As I mature, I have come to value plants with connections to our being but also the value of similar plants that can provide the same nostalgia while giving us much more in the landscape.

A plant known as Riverbank sundrops may be a perfect example of a great garden plant that is native to the Southeast and provides more of what gardeners love, while also providing the native insects and other wildlife an abundant resource.

Oenothera riparia was described by Thomas Nuttall in 1818 from plants collected along the Cape Fear River near Wilmington, NC. Nuttall provided a very full description of the plant (for the time) though he presumed it to be a biennial—it is in fact a long-lived perennial. J.K. Small recognized the species in a segregate genus as Knieffia riparia in his 1903 Flora of the Southeastern US. In 1937, Munz reduced the species to varietal status as Oenothera tetragona ssp. glauca var. riparia, and after this it was essentially lost to the minds of taxonomists and plant enthusiasts being considered merely part of the immense variability of Oenothera fruticosa by Radford, Ahles and Bell (1968).

In the mid 1990’s while working in the tidal freshwater swamps and marshes of South Carolina, Richard Porcher and I encountered this species growing at the bases of Bald Cypress trees, on stumps, and on floating logs just above the high-water tidal line on the Waccamaw, Pee Dee, and Edisto Rivers. My frustration with its identification led me to the name Oenothera riparia and its recognition as a completely and consistently distinct taxon—which is very unusual in a genus known for its morphological variability and messy taxonomy.

Oenothera riparia

This plant is smooth (lacking hairs) throughout with thick textured dark-green leaves and a very bushy habit—it does not produce long stolons or rhizomes, so it forms a dense clump. The stems generally range from a foot to nearly 3 feet in height and the thick stems become semi-woody, providing a stiffly upright growth form. Rather than a single burst of flowers this species produces masses of flowers over the entire summer (June-late August) with sporadic flowering later in the season.

Imagine, here we could have a sundrop that won’t spread like wildfire, doesn’t flop, and flowers for month after month! Sounds like everything you would want in a plant. There is only one problem, it hasn’t been cultivated. This is where the adventure continues and as we embark on this adventure, I would like to take you along for the ride. There is so much that goes into identifying a potentially great garden plant, evaluating it, and bringing it to the trade.

Our initial collections were made this August (2022) when Zac Hill, my wife Waynna, and I were traveling through the SC coastal plain. We made the stop at the Edisto River in Colleton County where I had seen the plant many years before and just like I remembered, there they were, full of seed and with some flowers still present. The only problem is that they were growing far out in the water along the bases of trees! The Edisto is a blackwater river with a large tidal amplitude at this location and it was full on high tide. If you’re a field botanist you forget entirely about the things that concern other more rational folks, like the multitude of large Alligators, and make for the plants. I found some low branches on a neighboring willow tree that kept my feet in only a couple feet of water, and balancing on the branch, in the water, made my way all the way to the edge of the river where a fabulous floating log provided an abundance of seeds and two small plants from a large cluster of individuals. The only casualty was my prescription glasses which promptly fell from my head into the depths of a rapidly moving Edisto River (my wife will not easily let me forget the cost of this single collection). The first step in the process of bringing a new plant into production is done.

Oenothera riparia

Our two small divisions were placed directly into the sun garden at JLBG and the seed was sown. For this plant to be successful in a garden it must be able to not just survive but thrive in a common garden condition far away from its very narrow niche at the very upper edge of the water along the Edisto. You might think this would be unlikely, but other incredible garden plants are entirely found in wetland communities and thrive under very different conditions in the garden. A good example of this is found in another of our introductions, Eryngium ravenelii ‘Charleston Blues’, which comes from high pH wetlands not too far away from the Edisto River.

Will it be hardy here? Will it survive under normal garden conditions? Will it maintain its distinctive and garden-worthy features? Well at least part of this can be answered already. Our tiny divisions are now large overwintering basal rosettes. The plants have not thought about running away from their tight cluster, and they grew very well during their first autumn in soil that was not kept overly moist.

The real test lies ahead. What will the plants nature be under cultivation? Will it be as good as I think it could be? Will it be better? One can only hope, put in the labor, and follow along to find out the end of this story for Oenothera riparia. It could provide all of us with a stately and handsome bit of nostalgia with far greater design and utilitarian use for humans and our native biota. What’s more, there are other seemingly great garden-worthy Oenothera out there—not in far-flung locations but right here in the Carolinas. Have you ever heard of Oenothera tetragona var. fraseri? If not, look for us to tell you more about that in the years to come, there’s a fantastic form with huge flowers in the Blue Ridge escarpment of South Carolina!

Patrick D. McMIllan, PhD

Arisarum, not Arisaema

A first cousin to the better known aroid, arisaema is the lesser known aroid, arisarum. While arisaema has a distribution that is primarily North American and Asian, arisarum is primarily European. We planted our first arisarums back in 1994, and since then have tried quite a few and killed quite a few. The best species for our climate is Arisarum vulgare, a Mediterranean native, found naturally in the countries of Albania, Algeria, Baleares, Corsica, Crete, Cyprus, East Aegean Islands, France, Greece, Italy, Lebanon-Syria, Morocco, Palestine, Sardinia, Sicily, Sinai, Spain, Transcaucasus, Turkey, and the former Yugoslavia.

With such a wide range of occurrence, some forms are naturally going to be more adaptable to our Zone 7b climate than others. The star in our trials has been a 2010 Crete collection of Arisarum vulgare from near the town of Lakki. From a tiny rhizome piece, it has spread to a 3′ wide patch. Like its’ other cousin, arum, arisarum goes summer dormant, re-emerging in fall. All of the previous forms of Arisarum vulgare we’ve grown have flowered only in early spring, but this amazing form flowers quite well every fall, in addition to being incredibly vigorous. We’ve just dug some of our patch today, and will work on propagating them for a future PDN catalog under the name Arisarum vulgare ‘Lady Lakki’. Hardiness is Zone 7b and warmer.

This collection of Arisarum vulgare is from Tony's 2010 expedition to Crete.
Arisarum vulgare ‘Lady Lakki’

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.

Green Goblet

Looking great in the garden this week is Agave x pseudoferox ‘Green Goblet’. This 1996 introduction from the former Yucca Do Nursery is one they found in Mexico and brought back as a single pup. Our original plant flowered in 2011 after 11 years in the ground, so this specimen has re-grown from one of the remaining small pups. Since we’re now at 11 years since last flowering, we’re preparing for a new blessed event. Since we can usually tell by now if it’s expecting, which it is not, the odds are pretty good for a 2024 flowering. Plant Delights Nursery will be offering A. ‘Green Goblet’ for sale in 2023.

An 11 year old plant of Agave x pseudoferox 'Green Goblet'.
Agave x pseudoferox ‘Green Goblet’

Happy about Hepaticas

I’ve been very blessed on several UK visits to spend time at the amazing Ashwood Nursery of plantsman John Massey. One of the real treats of each visit is a chance to spend time in John’s private hepatica greenhouse. To say John is a bit obsessive about the genus is a grand understatement, so it should be no surprise that he has channeled all that knowledge into a new Hepatica book, that’s hot off the press.

My World of Hepaticas - newly published book by John Massey and Tomoo Mabuchi

We first learned of John’s obsession with the genus, when he joined us on a 2000 expedition through NC, SC, Alabama, and Tennessee to study the hepatica in the wild…along with our main goal of studying trillium. Below is an image from that expedition. Hepatica are also native to Asia.

Hepatica americana var. acuta in situ 2000
Hepatica americana var. acuta in situ 2000
John Massey with Hans Hansen in the Hepatica greenhouse
John Massey with Hans Hansen in the Hepatica greenhouse
Image of Ashwood Hepatica greenhouse
Ashwood Hepatica greenhouse

Our copy of My World of Hepaticas arrived recently, and John’s book is a massive 296-page compendium of pretty much anything you’d want to know about hepaticas, compiled from John’s decades of work with the genus. John’s writing style is easily readable, coming across as if you’re having a relaxed conversation over dinner, and the incredible photos are an equal match to the text. Right now, you can only obtain a copy by ordering it from the Ashwood website.

Delavayi’s Schefflera

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.

Schefflera delavayi in flower at JLBG
Schefflera delavayi in flower

A new hardy yellow-flowered Begonia from Arunachal Pradesh

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 at Heronswood
Begonia lorentzonii
Begonia lorentzonii starting to bloom
                Begonia lorentzonii

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

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

Angel Wing

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.

Begonia taiwaniana 'Alishan Angel' thriving in a woodland garden
Begonia taiwaniana ‘Alishan Angel’

Opening up a Mis-can-thus of worms

Flowering this week at JLBG is the amazing Miscanthus transmorrisonensis. Many gardeners, who blindly believe everything they read/hear think the genus miscanthus is the horticultural version of the devil itself. Like everything in life, it’s all about those pesky details, which so many people simply don’t want to be bothered with.

Most miscanthus in the horticultural trade are selections of the species Miscanthus sinensis. Some selections of that species reseed badly and should be avoided in gardens. Others are sterile or nearly so, and unquestionably still deserve a place in American landscapes.

If we make good/bad evaluations at the species level, what would happen if visitors to the earth had their first encounter with a Homo sapiens that was a less than ideal representative of the species at large. They could easily assume that the entire species was a problem and should be eliminated. It’s fascinating that such species based prejudices are acceptable with ornamental plants, but not with people.

Then there are species, which have proven themselves to be complete without seed in our climate, such as Miscanthus transmorrisonensis. All plants in cultivation all appear to be derived from a 1979 Ferris Miller (Chollipo Arboretum)/ Paul Meyer (Morris Arboretum) collection at 9,500′ elevation on Taiwan’s Mt. Daxue. We have grown this for 30 years in rather good conditions, and have yet to see a single seedling. The beauty of this species is that it flowers continuously from summer into fall. I guess it’s too much to ask for environmental fundamentalists to actually pay attention to facts.

A large clump of Miscanthus transmorrisonensis
Miscanthus transmorrisonensis

More Amorphas

The genus amorpha is a woody cousin to the better know genus baptisia in the Fabaceae (pea) family. Amorpha was named a genus by Linnaeus (perhaps you’ve heard of him) because the flowers only have a single petal, compared to 5, which is the norm in the rest of the family. Virtually all amorphas have many uses, from dyes to treating an array of medical conditions. There is an amorpha native in every one of the Continental United States…how many do you grow?

Our longstanding favorite member of the genus is the Midwest native Amorpha canescens, which makes a stunning, compact deciduous shrub, adorned in late spring with amazing, pollinator friendly flower spikes.

Amorpha canescens
Amoropha canescens

While we had our back turned, one of our Amorpha canescens got jiggy with a nearby Amorpha fruticosa, and the baby below, discovered by our staff, has now been adopted by us, and named Amorpha x frutescens. We actually might have some of these show up in the spring Plant Delights catalog.

Amorpha x frutescens (fruticosa x canescens)

Another amazing Southeast US (NC to FL) native species we like is Amorpha herbacea. Although it is rarely available, we think this has exceptional garden value and will most like show up in the Plant Delights catalog in the coming years.

Amorpha herbacea

Christmas in June

While doing some local botanizing recently, we ran across this fascinating form of our native Christmas fern, Polystichum acrostichoides. Not only was it more compact than any others in the area, with more “orderly” fronds, but it also showed none of the typical terminal spore production that would be expected this time of year. Since this was from a future development site, the plant was rescued, and is now at JLBG under evaluation. The second photo is more typical plant for the species for comparison, growing at JLBG.

The Thrilla of Cyrilla

If you’ve been following our blog for a while, you’ll remember we wrote about this amazing native shrub/small tree last summer. Well, it’s cyrilla time again in the gardens at JLBG, when every branch of this amazing semi-evergreen erupts with racemes of small white flowers, inviting all insects in the neighborhood to stop by for happy hour. This standard form of Cyrilla racemiflora pictured below, usually matures in the 10′ to 12′ range with a spread that’s double the height. Although it is found in the wild growing in moist, sandy soils, it grows equally as well on clay soils, as long as droughty periods don’t extend too long.

Cyrilla racemiflora

We think the most exciting horticultural addition to the world of cyrillas is a dwarf, witches broom discovered by Georgia botanists, Ron Determann, and the late Tom Patrick. A witches broom is a dwarf mutation with very short internodes, most often associated with conifers. Ron allowed us to introduce this amazing plant, which he named in Tom’s memory, Cyrilla racemiflora ‘Tom Patrick’. The density of branching and size is quite amazing. Since this selection is so new, we aren’t really sure of a mature size, but we’re guessing about 6′ in height.

Cyrilla racemiflora ‘Tom Patrick’

Oldham’s Azalea

Few gardeners have probably grown the Taiwanese Rhododendron oldhamii, but this little-known species has become one of the most important azaleas in American horticulture. Here it is flowering in our garden in late spring. Then will be followed by a late summer/fall rebloom.

Rhododendron oldhamii was named for British plant explorer Richard Oldham (1837-1864). Here’s a fascinating summary of Oldham’s life/work. Despite dying at the young age of 27, Oldham made significant contributions to botany, including the rhododendron (azalea) named in his honor.

In the early 1980s, Louisiana nurseryman, Buddy Lee decided to see if the fall reblooming trait of Rhododendron oldhamii would transfer to its offspring. Indeed they did, and because of Richard Oldham his namesake azalea, and Buddy’s imagination, we now have an entire series of reblooming azaleas, known as the Encore azaleas.

Hi Jacks

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.

Arisaema triphyllum Wake County, NC

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.

Arisaema triphyllum silver veined clone
Arisaema triphyllum silver veined clone with green stems
Arisaema triphyllum silver veined clone with purple stems

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.

Arisaema triphyllum with rust induced pattern
Arisaema triphyllum rust induced pattern on leaf back

Buttercolor

Here are a few buttery-colored plants flowering today in garden, starting with Arum creticum ‘Golden Torch’. This started as a small field division of a particularly large flowered selection from our 2010 expedition to Crete.

Arum creticum ‘Golden Torch’

Paeonia mlokosewitschii is known for being un-pronouncable, so most folks refer to it as Molly the Witch peony. This is a particularly lovely butter yellow form from Ellen Hornig of the former Seneca Hill Perennials.

Paeonia mlokosewitschii JLBG-03

Trillium sp. nov. freemanii is a still unpublished new trillium species (hopefully soon), that we discovered in 1998. Normally red flowered, this is a rare yellow-flowered form.

Trillium sp. nov. freemanii JLBG-014

Oh, Daphne

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 collina

Daphne ‘Rosy Wave’ is a Daphne collina hybrid with Daphne burkwoodii

Daphne ‘Rosy Wave’

Daphne x napolitana ‘Bramdream’ is a hybrid of Daphne collina and Daphne cneorum.

Daphne x napolitana ‘Bramdream’

A Forest of Pink

Magnolia ‘Forest’s Pink’ put on a splendid show this year in early to mid-March. Sold as a cultivar of the Chinese Magnolia denudata, some magnolia experts insist that it’s actually a hybrid, due to the intensity of the pink color as well as the form of the plant.

Magnolia ‘Forest’s Pink’ originated as an introduction from Treseder’s Nursery in Cornwall, England, who propagated and named it from an original introduction from China by Scottish botanist, George Forrest (1873 – 1932), that was growing at England’s Caerhays Castle.

Magnolia denudata, a typically white-flowered species, native to Central China, has been cultivated around Buddhist monasteries since 618 AD…in other words, nearly 1,500 years. Another long-cultivated Chinese native magnolia with pink flowers and an overlapping native range is Magnolia liliiflora. The commonly known hybrids of the two species are known as the Magnolia x soulangeana hybrids. Since plant explorer George Forest was known to collect both in the wild as well in cultivated areas, it is quite probably that the magnolia that bears his name is not pure Magnolia denudata, but actually a Magnolia x soulangeana hybrid. Looks like someone will need to do some DNA work to sort out this nomenclatural tussle.

Whatever you want to call it, our 25 year-old specimen of Magnolia ‘Forest’s Pink’ was rather stunning this March. Thankfully, the flowering was mostly complete before our mid-March freeze of 23 degrees F.

An Exciting New Expedition

Please join me in welcoming our newest JLBG team member, Dr. Patrick McMillan. I’ve known Patrick for 30 years, going back to his days as a student at UNC-Chapel Hill, and long before he became a legend in the plant world.

We’ve followed his amazing journey, most recently as Director of Heronswood Gardens in Washington. Prior to that, he was Director of the SC Botanical Garden and Professor of Environmental Sustainability at Clemson since 2000. Patrick was the Emmy Award winning host of the renown PBS series, Expeditions with Patrick McMillan. Patrick is a highly-respected botanist/naturalist, who has won far too many awards to mention, but we’ll let Patrick tell you a bit more about himself and why he decided to partner with JLBG.

My first experience with Juniper Level and Tony was sitting at the kitchen table in 1991, the inaugural year of Plant Delights Nursery, talking about Asarum and star-struck by Tony’s knowledge and passion that has continued to grow into one of the world’s premier gardens and nurseries. In those days I dreamed of the opportunity to work alongside such talented horticulturalists and intrepid explorers.

My love of plants and all things slithering, creeping, crawling, and flying came at a very early age. I can’t remember a time when my life wasn’t centered on them. Fast forward 31 years and I found myself sitting at the same table reminiscing about the past, marveling at how far JLBG has grown, and stirring excitement for the future. I am so enthusiastic about joining the staff at JLBG, learning from the lifetimes of incredible knowledge and skill that is assembled among the employees and sharing my own experience, passion, and knowledge to bolster the mission and the horticultural and conservation accomplishments of this magical place.

I’m probably best described as a plant nerd. I have never met a plant I didn’t love. Every plant has a story and each is connected to our lives and the lives of the biodiversity upon which we all depend. Much of my horticultural experience and focus in South Carolina and at Heronswood Garden in Kingston, Washington has been focused on generating and supporting insect, bird and other wildlife diversity in the home landscape.

My philosophy of natural community gardening and the generation of life is a fairly simple one based on filling every space with life – diversity generates diversity. My exploration of the plant world has taken me from pole to pole and over every continent except Australia. I was trained as a sedge taxonomist but my interests include anything with cells. I’ve described new species ranging from ragweeds to sedges and begonia.

I also believe strongly that our greatest gift is sharing knowledge and I have worked as a lifelong educator. You may also have seen me on your local PBS station, where for 15 years I wrote, hosted, and produced the series “Expeditions with Patrick McMillan” – distributed by American Public Television. Conservation, preservation and generation of life is at the core of my life’s mission and I can imagine no better place to be nested within than JLBG. I hope to meet you soon and share some hearty plant nerd conversation.

Brexit Redux – Part IV

Our next focus was to re-purchase plants that we had picked up on our 2018 trip, but due to a bureaucratic shipping snafu, the majority of the 2018 shipment was killed during a six-week delay in transit. These pick-up stops included a couple of personal favorite nurseries, Cotswold Garden Flowers and Pan-Global Plants, as we worked our way south. One new stop was in Devon, at a wholesale woody plant propagator, Roundabarrow Farms, whose owner Paul Adcock had visited PDN/JLBG the year prior.

Although Paul had no electricity at his remote nursery location, he was kind enough to allow us to use his open potting shed for our bare-rooting chores. For those who have never shipped plants internationally, the process is at best arduous. First, you must check the extensive USDA list to see which plants are allowed entry into the US. Next, plants must be bare-rooted and scrubbed free of all soil and potential pests. For a shipment of 100+ plants, this operation takes about 8 hours. This was the first time I’d had the pleasure of doing the tasks outdoors in the snow, rain, and gale force winds. Thank goodness darkness coincided with the onset of frostbite.

Plant wrapping was finished that evening and the following morning at our room nearby, which wasn’t dramatically better than Paul’s potting shed, since the bathroom was not attached to the room and the strung out property manager kept turning off the heat to the room.

Our final stop in Southern England was at Tom Hudson’s Tregrehan Gardens in Cornwall. This was my first trip to Cornwall, but after hearing that Tregrehan was the finest woody plant collection in the entire UK from several of the UK’s best plantsmen, it was not to be missed. I will admit that all the talk I’d heard about the mild climate of Tregrehan, I wasn’t expecting the frigid weather we encountered including intermittent sleet and snow.

Tom Hudson, Owner

We had the pleasure of walking the amazing collectors garden with Tom and his dogs. Despite the difficult weather, we had an amazing visit as we walked among many of the towering specimens, many of which were 150 years old.

Boulevard Cypress (Chamaecyparis psifera ‘Squarrosa’ @ 150 years of age. Look ma…it isn’t so dwarf after all.
Fatsia polycarpa ‘Needham’s’ was in full flower
It was great to see the giant leaf selection of Fatsia japonica ‘Hsitou Giant’ as well. Tom had shared one of these for our 2019 Southeastern Plant Symposium auction. Perhaps another will show up for the 2020 auction.
Huodendron is a plant I’ve killed four times, but three of those times, it died before even making it into the ground. What an amazing specimen of this evergreen styrax relative.
Illicium simmonsii was in full flower, as was this still unidentified species.
Tregrehan has a wonderful collection of hardy scheffleras, most of which are sadly ungrowable for us because of our hot summers.
Not bad for a specimen of the US West Coast native Douglas Fir.
Rhododendron were everywhere including some early flowering species
It was hard not to be impressed by 150 year old specimens of Rhododendron arboreum.

The ideal time to visit Tregrahan is during their Rare Plant Fair and Sale, held every year in late May/early June (the plant fair is currently under review, due to the fast moving nature of the Coronavirus). Vendors and the foremost plant collectors come from all over the world to this amazing event.