Back in 2018, I spotted a listing for Korean germplasm of Magnolia sieboldii on the seed exchange list for the International Magnolia Society. For those who don’t know magnolia species, Magnolia sieboldii is considered one of the most beautiful in the genus, but it’s widely known not to grow in hot, humid climates. I had actually seen this pendant-flowering species on Korea’s Mt. Sorak in 1997, but didn’t gather seed because I assumed it ungrowable. Subsequent to that trip, we would try in our garden, but we stopped after killing it on our requisite three attempts. Good sense would tell us to stop trying, but that’s not something we seem gifted with.
As with all plant breeding and selection, it’s a numbers game. If the desirable trait exists in the species, you’ll eventually find it, if you grow enough seedlings. Since there were plenty of seed available from the exchange, I reasoned that if we grew enough, perhaps one would show some heat tolerance.
I don’t remember exactly how many pounds of seed arrived, but they were promptly sown, and germination soon followed. Each time the seedlings were transplanted, only the most vigorous ones were selected. These were then grown in our research cold frame for the next year, subjected to full sun and through a typical NC summer. By the following spring, we had whittled down our selections to nine clones that had thrived in containers, and in early spring 2019, they were planted in the ground. Over the ensuing years, four passed away, leaving five. This spring, four years after planting, two clones have topped 7′ in height and are flowering beautifully, as you can see below.
There are less than 20 named selections of Magnolia sieboldii, most selected either for double flowers or blush pink tips, but none for heat/humidity tolerance. The next step will be to make a final selection which we’ll name Magnolia sieboldii ‘Southern Pearls’. Scion wood will then be shared with Magnolia grafters who will assist with our mission to propagate and share. Winter hardiness of this clone should be at least Zone 5b – 7b.
We’ve been playing around with growing bletilla orchids from seed. After growing several thousands from seed, we’ve settled on a few selections for production trials. Below are a few of those that we feel are unique enough from the selections already on the market.
This winter is the first time in many years that we were successful at overwintering Pleione orchids in the ground. Up till now, we’ve killed our 9 other attempts. This time, our success was with the cultivar, Pleione ‘Alishan’, a hybrid of Pleione formosana and Pleione limprichtiii.
We’ve done a deep dive to see how much potential there is for these to grow outdoors in our region. Of the 24 Pleione species, native from India into Asia, it seems that 11 of them should be fine in our climate. That list includes P. aurita, bulbicoides, chunii, formosana, forrestii, grandiflora, hookeriana, humilis, limprichtii, pleinoides, and yunnanensis.
The other Pleione species either grow in elevations that are too low or too high. There seems to be more factors at work in determining how well they grow, other than low temperatures, since most Pleiones prefer to grow in duff, as opposed to heavy soil.
Over the next several years, we hope to trial more of both the species and the nearly 450 cultivars, which have parentage that predict their growability in our climate.
It was great to spend several days last week walking through the nursery and gardens with our dear friends, Carl Schoenfeld and Wade Roitsch of the former Yucca Do Nursery. Wade is still gardening and plant exploring in Texas, while Carl has opened Yucca Doo Vivero at his home in Salta, Argentina. You can follow his new adventure on Facebook.
Their contributions to the world of horticulture are extraordinary, and it’s great that those efforts are continuing, despite the closure of their North American operation.
In late February, myself and local plantsman Mike Chelednik, headed south for the mid-winter meeting of the Southeast Palm Society, being held at the American Camellia Society Headquarters at Massee Lane in Ft. Valley, Georgia. I had wanted to visit the camellia garden ever since I knew one existed, but the timing had never worked out. Mike, who goes by the social media moniker, “Mike See”, is one of the foremost camellia experts, as well as a hardy palm enthusiast.
Our first stop on the way to Ft. Valley was the Atlanta Botanical Garden’s Gainesville, Georgia satellite garden, to check out the plant damage from their winter low temperatures of 5 degrees F. Although a number of plants in their trial fields were quite crispy, including most of the commercial cultivars of distyllum and even giant plants of Osmanthus heterophyllus, there were an amazing number of new plants from their recent Asian plant exploration trips that sailed through the cold.
I was particularly excited to see that a collection of the giant Begonia sillitensis from India sailed though the cold and looked ready to start growing. It was also great to see how well their large specimen of the Taiwanese aralia relative, Sinopanax formosanus, sailed through the winter. I had seen this in the wild several years earlier and felt it had a good shot at surviving in central NC.
I was especially glad to see that their amazing, conical clone of the hardy cinnamon tree, Cinnamon japonicum sailed through the low temperatures without any damage.
Their greenhouse was full of new treasures yet to go in the ground, including this Vietnamese collection of Sauromatum venosum. Virtually all of the material in the trade currently is from India, so these new genetics are quite exciting. Of course, there is always the possibility that this constitutes a newly discovered species. The velvety leaf surface makes me fairly confident this may be new. We are very fortunate to be a trial site for many of their amazing collections.
From ABG, we headed south through the highway insanity that constitutes the drive through Atlanta and south toward Macon, GA. There simply aren’t enough lanes to handle the mass of vehicles that travel this route–something you would think highway department officials would have noticed by now.
I was quite unprepared for the facilities at Massee Lane Gardens, since plant society headquarters are pretty much an extinct dinosaur of bygone eras. In this case, the Ft. Valley headquarters located in this former peach shipping hub of South Georgia, was a well-funded throwback to earlier generations. Started in the 1930s by pecan farmer, David Strother, the 160 acre property still contains pecan orchards. In 1966, Strother donated the property to the American Camellia Society.
The rectilinear facility has a “dripping with money” elegance, at odds with most of the surrounding tired town. Entering through the gift shop, a right turn takes you into the Annabelle Lundy Fetterman Educational Museum, a meeting room/display museum, which houses an absurdly extensive collection of Boehm porcelain. This room is named after the NC camellia aficionado of the same name. The late Annabelle Fetterman was the renown businesswoman CEO/owner of Clinton NC’s Lundy Packing Company.
Taking a left from the gift shop, routes you toward the lovely auditorium, where we would hold our Palm Society meeting.
About 35-40 palm nuts showed up for the SPS meeting, with several like us, driving in from 5-10 hours away. I’ve been a member of this amazing, but loose knit organization, for over 3 decades, although I think this is the first meeting I’ve attended that wasn’t held at our own Raleigh garden. We were treated to a fascinating talk by Rick Davis, on growing Cocoid palms in upstate SC. These include the jelly palms of the genus, Butia, and their hybrids. I think we all left the meeting, knowing there are far more palms we need to try in Zone 7.
Following the meeting, there was a rare palm auction thanks to member donations, followed by a tour of the Massee Lane gardens by Garden Manager, William Khoury. William and his staff of one assistant, manage and curate the entire camellia garden, which covers over 6 of the 160+ acre property. We’re sending good thoughts that they get more help to manage this extensive collection.
The garden is almost exclusively camellias, planted in large beds, with easily navigable paths winding visitors through the plantings.
While 99% of the visitors head to the garden section containing the show camellias and their hybrids, I headed to the virtually empty section devoted to wild camellia species, almost all of which were a gift from the late Dr. Clifford Parks of Chapel Hill, NC, just prior to his death. It was an interesting study, since they dropped to 12 degrees F. this winter…only a single degree higher than Raleigh, NC.
Camellia species other than Camellia japonica, Camellia sassanqua, Camellia reticulata, and Camellia sinensis, are virtually unknown by US gardeners. While not nearly as showy as the fancy hybrids, many of these plants have amazing foliage and forms, with most worthy of garden inclusion.
For the first several hours, I had the species collections to myself, until after an on-site food truck lunch, I heard a female voice recording a soliloquy about species camellias as the figure slowly sauntered from plant to plant. As I peered through the thicket, the voice was coming from none other than our NC neighbor and former PDNer, Brie Arthur of Brie Grows, who was in the area, recording a camellia segment for her Youtube channel.
By late afternoon, I had finished studying the species, and made my way over to the show camellia garden. Much of Massee Lane is devoted to camellias that are grown for flower show bloom competitions/displays. Below are a few photos from the acres of mostly well-labeled plants. There are certainly few better gardens in the southeast US to see this many camellias (over 1,000 plants) and make notes of which you’d like for your own garden. There was even a sales area devoted to some rather new and hard to find hybrids.
Heading back north toward home, we made one stop at the garden of Atlanta area plant collector, Ozzie Johnson, who maintains a large collection of mostly Asian plants at his extensive garden. As we saw at Atlanta Botanical Garden, there was extensive damage due to the single digit F low temperatures in December.
A huge specimen of Aucuba omeiensis was quite fried and we were unable to determine yet if it might possibly resprout.
The original plant of Ozzie’s introduction, Mahonia ‘Soft Caress’, also was completely defoliated, although it appeared like it would resprout.
Another of Ozzie’s introductions, the weeping Japanese maple, Acer palmatum ‘Ryusen’ was untouched. The photo is of the original plant from which all others have been propagated.
Despite most of the commercial selections of Distylum being fried, it was great to see this variegated selection of Distyllum myriocoides untouched after 5 degrees F.
Carex picta ‘Bama Beauty’ is looking particularly wonderful in the garden today. Native from Indiana south to Mississippi, this little-known sedge has been delighting us in the garden since 2014, when Zac Hill, JLBG’s Taxonomist and Plant Records Specialist, brought a piece back from a botanizing excursion to Alabama.
In the garden, it’s been very slow to multiply, but we hope to make this available before too much longer. Carex picta is an oddity in being one of very few sedge species that are dioecious–plants are either male or female. This collection is a male selection, which has more showy flowers–as carex go.
We’re several years into an experiment to see how well the epiphytic (grow mostly on trees) tongue ferns of the genus Pyrrosia fare in hanging, moss-lined baskets when left outdoors all year. This is our coldest winter to date since the test began, with a low of 11 degrees F. Here is a photo of one of those baskets taken today. They were not protected in any way during the cold. We have 17 clones on trial in this manner, and some do show a bit of foliar damage, while others are untouched. We think it’s quite amazing to have evergreen hanging baskets of live plants that can remain outdoors here in Zone 7b.
One of the nice surprises this winter has been the performance of our hybrid Magnolia grandiflora x Magnolia coco. This 2019 seedling came through the recent 11 degrees F looking great, despite half its parentage being rather tender.
While Magnolia grandiflora is certainly winter hardy here, the other parent, Magnolia coco is “reportedly” not hardy. Magnolia coco is a small tree/shrub hailing from Vietnam, Southern China, and Taiwan. Those reputable on-line sources consistently write that it isn’t hardy north of Zone 9. Well–hmmm!
The bottom image is our plant that has been in the garden since 2003…that’s 20 years. Yes, after 11F, the foliage is brown, but the stems are fine and it will re-flush well in spring. We can’t wait to see the flowers on the hybrid, which is still a few years away from being old enough to have sex.
We were thrilled to see how well our Mexican bear grass, Nolina hibernica fared through our recent cold. We had lost this ten times previously, and were close to giving up, but decided to plant this one in a partially shaded site. Previously, we had only planted these in full sun, where they thrived except during cold winters. By growing this partially under shade, it reduces the amount of cooling on cold nights by having a tree canopy nearby. This 8 year old specimen has a way to go before it reaches its potential mature height of 20′. Fingers crossed.
11 degrees F was a bit more than our clump of Massonia depressa had hoped for. Although the cold temperatures burned a bit of one leaf, it not only survived, but is now in full flower. That’s pretty amazing for a South African bulb that Wikipedia authoritatively states “does not tolerate freezing temperatures”. Rock on!
One of the nice surprises after our 11 degree F freeze was how well our Escallonia ‘Iveyi’ fared. Few people on the US East Coast are familiar with these South American woody members of the Escalloniaceae family.
Escallonia ‘Iveyi’ is actually a hybrid that originated at the UK’s Caerhays Castle, where it was discovered as a seedling between Escallonia rosea and Escallonia rubra. Our plant should mature at 10′ x 10′. In mid summer, this amazing selection is smothered in fragrant white flowers.
All the literature we’d been able to find, indicates it is only hardy to 14 degrees, but that’s another reason we don’t let our plants read gardening books or browse the Internet. Our plant was grown from cuttings from an old specimen at the SC Botanical Garden in Clemson.
I had to chuckle as folks on several Facebook plant groups were wringing their hands in worry prior to the recent cold snap, while we were secretly hoping for even colder temperatures than forecast.
JLBG registered three consecutive nights in the teens recently; 11F, 19F, and 19F. While this was certainly not abnormal for our area, folks with very short memories thought the horticultural world was coming to an end. In reality, we recorded similar temperatures in the winter of 2017/2018, albeit a week later that year.
When we first started the gardens at JLBG, we were squarely on the Zone 7b side of the Zone 7a line. We are now on the Zone 7b side of the Zone 8a line. In order words, we have shifted about 1/4 of a hardiness zone. Since 2018, JLBG has registered three consecutive Zone 9a winters, so it’s not surprising the new gardeners or those with short memories start assuming that all kind of plants are reliably winter hardy, which is not the case.
We long for cold temperatures because we want and need good winter hardiness data, and while mild winters may be enjoyable to us Homo sapiens, we don’t learn anything about plant hardiness from those winters. So, here are a few things we learned this year.
Agave weberi ‘Stone Cold Austin’ is Patrick McMillan’s collection of Agave weberi from Austin, Texas. We’ve tried Agave weberi a couple of times prior, and could never get it through one of our milder winters. Patrick’s original plant at Clemson got large enough to flower there, so we’re hoping for the same. The older foliage is showing damage from 11F, and will most likely be lost, but the bud seems fine so far.
We’ve never had any luck with any of the dwarf Agave lechuguilla mutants we’ve tried in the garden, but this new one, shared by plantsman Hans Hansen, that we call Agave ‘Tater Tot’, had no problem with 11F. These are often sold as Agave x pumila, which actually doesn’t exist. Everyone assumed that A. x pumila was a hybrid, but when one in Europe recently mutated back to the original form, it turned out to be nothing more that a super dwarf form of Agave lechugullla.
Mangave ‘Racing Stripes’ is a plant we had high hopes for in terms of winter hardiness, but we had not had a cold enough winter to get good data. Our only reservation was that it contains genes from the tropical Agave gypsophila. Thankfully, our plant came through the 11F freeze in reasonably good shape. The wrinkled nature of the older leaves are indications of cold damage that will show up in a few more days, but the core seems intact and should re-grow.
We fully expected Bambusa multiplex ‘Green Giant’ to be defoliated after 11F and the stalks killed to the ground, but our fully exposed clump still looks like it’s mid-summer…at least from the north side.
On the south side, the same clump has fried foliage. There are typically two causes for such damage. One is wind desication when the winds are blowing from a single direction and the ground is frozen, making it impossible for the plant to replenish water lost through the foliage. During the time that our ground was frozen, our winds were coming from the West, so that wouldn’t account for damage only on the south side of the plant.
In this case, the more likely scenario is that this is due to sun scorch when the soils was frozen, since the damage is on the south side. If the canes are indeed undamaged, as it appears, new leaves should reflush in spring.
We didn’t hold out much hope for the Mexican palm, Brahea decumbens, but it sailed through 11F unscathed.
Since we know that genetics matters, we will often plant more than one clone of a marginal plant like a new palm. Below are two seedlings of the small-seeded European Fan Palm, Chamaerops humilis var. microcarpa. The first shows significant foliage burn, while the second plant, growing nearby shows no damage after 11F.
The hardiest of all Sabal palmetto forms are those from NC’s Bald Head Island. Our plant from there came through the cold unscathed. We expect many local businesses and even homeowners who purchase large trunked forms directly from Florida growers will probably be in for a disappointing spring.
All of our hardy cycads have assumed the straw-color we see every year when the temperatures drop below 18 degrees F. The plants are fine, but we recommend waiting to remove the dead fronds, since doing so now, can cause the new foliage to emerge in the middle of winter, which is never a good idea. April 1 is our target date to remove the fried foliage.
One of the real surprises was the fried foliage of Viburnum ‘Moonlit Lace’, where it was growing in full sun. The same plant growing in shade looks untouched. The stems are fine and the plant should re-sprout fine, but gardeners who grow this in full sun may be disappointed.
This is the coldest temperatures we’ve seen since planting Patrick’s hardy selection, Opuntia microdasys ‘Dripping Springs’. Our clump looks great after the cold. It’s hard to imagine that this clone is so much more winter hardy than any of the other forms of this species that we’ve tried previously and killed at much warmer temperatures. Although we don’t offer this for sales, I’ll remind you of our great prickly pear cactus giveaway at our Summer Open Nursery and Garden in July.
The Mexican Sedum praeltum looks a bit sad, but actually seems to be fine with sound buds up and down the stem. This little-known perennial forms a plant that looks almost exactly like the tender Jade plant, Crassula ovata.
Lastly, our patches of Living Stones, Lithops aucampiae, sailed through 11 degrees F. I wonder if we can ever get all the disinformation on the Internet regarding their tolerance to cold corrected.
We’ve long been enamored with the Southwest native genus of slow-growing woody lilies belonging to the genus, Dasylirion. Since the early 1990s, we’ve been growing these, trialing as many species as we could obtain to see how well they adapted to our climate here in the colder, wetter Southeast.
So, far, we have grown 16 of the 21 recognized species and succeeded with 12. We found four unable to survive our coldest winters, including Dasylirion durangensis, Dasylirion longissimum, Dasylirion lucidum, Dasylirion sereke.
The five species we have yet to try in the garden are Dasylirion graminifolium, Dasylirion longistylum, Dasylirion micropterum, Dasylirion palaciosii, and Dasylirion simplex. We have seed planted of both Dasylirion graminfolium and micropterum, so those will be next in line for our in ground trials. That leaves us still searching for seed of the final three.
Sotols, like agaves, are members of the Asparagus family. They are becoming wildly popular, but not because of gardeners. Instead, their popularity is driven by those who are driven by a need/desire to imbibe alcoholic spirits. First, there was Mescal, a Mexican drink made from one of a number of different agave species, depending on what grew in proximity to each village. Of the Mescals, the most popular is Tequilla, which is made from a single species, Agave tequiliana.
Now, Sotol alcohol has joined the ranks of the “hot new spirits”. Made from agave’s cousin, plants of the genus Dasylirion, Sotol is rapidly becoming the new “flavor of the month”. Sotol alcohol certainly isn’t new, and if you regularly travel south of “the wall” you probably already know that Sotol is the state drink of Mexican states Chihuahua, Coahuila, and Durango.
Not so long ago, Sotol alcohol had a history that somewhat parallels moonshine in the Southeast US. For years, Sotol alcohol was illegal and subject to government raids, during which master sotoleros were punished or imprisoned. During the US prohibition of the 1920s, Sotol sales in the US skyrocketed, but soon after its repeal, Sotol sales plummeted back into obscurity. Now, with not only social acceptance, but a wide wide embrace of virtually anything that can be used to produce alcohol, Sotol has been mainstreamed with the assistance of the Mexican government and willing marketers.
Most agaves for Tequila production are now commercially grown in massive farms, and most plants are now produced from tissue culture for a more consistent yield and to take pressure off wild popuations. Even under ideal farming conditions, it take 5-7 years to get an agave large enough to harvest for tequilla production. With dasylirions, the same process takes at least 12-15 years according to Sotol marketers. Based on our 30 years of work with the genus, I’d say the time involved is more likely 24-30 years, even in a high rainfall climate like ours.
I’m not aware of many farm operations that can afford to grow a plant for that long before expecting a return on investment. This means that poaching of plants from the wild is very likely to increase. With such a low rate of return, i.e. 1 pint of liquor for each plant harvested, I can’t see the plants coming out on the good end of this industry. While making alcohol from dasylirions isn’t new, it’s been done on a very limited scale in Mexico, prior to word spreading around the world via social media.
Reportedly Sotol spirits taste quite different based on the species used, and whether it’s from an exceptionally dry region or an area with better rainfall. Sotol conniseurs describe the tastes as being a bit like menthol or pine/mushrooms if the plants are grown well hydrated, while those from drier regions taste more like leather. To quote Dave Barry, “I’m not making this up!” And this sounds appealing to who???
Supposedly, the spirit producers are cutting off the wild dasylirions and leaving the bases to resprout, but I’ve got my doubts about how well that works. Assuming the cut dasylirion does resprout, there will be a decade of lost seed production, so plant populations in the wild are almost certain to decline. I’m left to wonder if we really are so desperate for a new taste in alcohol that we are willing to sacrifice another genus of plants in the process.
In celebration of these amazing plants, here are photos of those we have grown in our ex-situ conservation gardens at JLBG.
Dasylirion acrotrichum, named in 1843, is native to Mexico’s Chihuahuan desert. Of the seven plants we planted, only one survived, which is now over 20 years old. This widespread sotol, which occurs on igneous soils, has been split by various authors into several subspecies. Undoubtedly, winter hardiness varies based on the seed procurement location. At maturity, the trunks can reach 5′ tall.
Dasylirion berlandieri, named after French/Mexican naturalist, Jean-Louis Berlandier (1803-1851), was first published in 1879. Native to steep rocky hillsides in Tamaulipas and Nuevo Leon in Northeastern Mexico, it’s one of the largest species in the genus in width, but with a trunk that never exceeds 1′ in height. Below is our plant in bud. Unlike agaves, dasylirion rosettes do not die after flowering.
Below is a fully open flower spike, which is abuzz with a large number of bees
Dasylirion cedrosanum, first documented in 1911, hails from 3,000′ – 6,000′ elevation on rocky, gypsum-laced hillsides in the Sierra Madre Occidental mountain range. They are restricted to the Mexican states of Chihuhua, Coahuilla, and Durango. At maturity, they produce a 3′ tall trunk.
Dasylirion durangensis is another species first described in 1911, which hails from the dry alkaline/limestone-gypsum deserts of Coahuila, Chihuahua, Durango, and Zacatecas. In parts of its range, it interbreeds with Dasylirion wheeleri. We flowered this prior to losing it during a particularly cold winter. Below is our Obit photo.
Dasylirion gentry was only published as a species in 1998. It has a very limited range between 3,500′ – 4,000′ in Sonora, Mexico, where it grows on rocky slopes in openings of pine/oak woodlands.
The inflorescense of Dasylirion gentryi is one of the most spectacular we’ve ever seen.
Dasylirion glaucophyllum is a species whose discovery dates back to 1858. It can be found naturally, only in Sonora, Mexico, growing on rocky hillsides at elevations to almost 8,000′. At maturity, trunks measure up to 6′ in height.
Dasylirion leiophyllum, published in 1911, only grows north of Mexican border in Texas and New Mexico. Based on where it grows, it should be one of the most winter hardy sotol species. The first photo is at JLBG, and the second in situ at 5,400′ elevation. The second image is from the late plantsman, David Salman, of a Zone 5 population he discovered and shared seed with us just prior to his untimely death. Plant Delights is currently offering this as Dasylirion leiophyllum ‘Chaves’.
Dasylirion miquihuanense, only described in 1998, hails from Tamaulipas and Nuevo Leon in Northeastern Mexico. Also occurring on rocky slopes, this sotol is one of the tallest species, producing massive 8′ tall trunks. We have succeeded long term with only 2 of 8 specimens we planted.
Dasylirion parryanum, published in that banner year of 1911, hails from up to 8,000′ elevation in the San Luis Potosi State in Northern Mexico, where it produces 3′ tall trunks.
Dasylirion quadrangulatum (1879) hails from the Southern (warmer) end of Tamaulipas and Nuevo Leon. It is much too tender for us to grow in the open here in Zone 7b, but we’ve kept it alive for a couple of decades by siting it in a microclimate adjacent to a brick wall house foundation. It is one of only two species lacking leaf spines. With great age, it produces trunks to 9′ in height.
Dasylirion serratifolium, first described in 1838, is from Oaxaca, Mexico, where is grows on rocky, alkaline hillsides to 6,600′ elevation. The location and elevation means it really shouldn’t survive our winter. That said, our only remaining specimen below is now 20 years old, but is still far from reaching the 6′ tall trunk height it does in the wild.
Dasylirion texanum (1850) is another very winter hardy species, found on rocky slopes, ranging from Central Texas into the mountains of Northern Mexico. It is one of the shortest species, with a trunk that doesn’t exceed 1′ tall.
Dasylirion wheeleri, first documented in 1878, ranges from Texas, Arizona, and New Mexico south into the mountains of Northern Mexico. It matures at 6′ tall, and in situ, can be found in both grasslands as well as openings in pine/oak forests. It is another of the most cold hardy species.
An old clump we planted years ago in flower is quite remarkable.
We hope you’ll limit your consumption of Sotol as a drink and instead join us in becoming an ex-situ conservation garden for this amazing genus of plants.
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.
Great new plants for the garden do sometimes just happen. They can occur as a spontaneous sport from an existing planting, as a seed selection that has much better garden traits, but many of our most useful and ecologically important plants in the garden have their start in exploration. I was thinking about this today as I observed the tightly-clumping overwintering rosettes of one of our newest introductions to the JLBG—Oenothera riparia, Riverbank Sundrop.
Sundrops hold a special place in my heart. My grandmother loved them and had large swathes of the old pass along yellow standard Oenothera fruticosa/tetragona in her extensive garden. Every June they would burst into flower for a brief week or so, bringing a brilliant light and foil to her many glorious iris. As I mature, I have come to value plants with connections to our being but also the value of similar plants that can provide the same nostalgia while giving us much more in the landscape.
A plant known as Riverbank sundrops may be a perfect example of a great garden plant that is native to the Southeast and provides more of what gardeners love, while also providing the native insects and other wildlife an abundant resource.
Oenothera riparia was described by Thomas Nuttall in 1818 from plants collected along the Cape Fear River near Wilmington, NC. Nuttall provided a very full description of the plant (for the time) though he presumed it to be a biennial—it is in fact a long-lived perennial. J.K. Small recognized the species in a segregate genus as Knieffia riparia in his 1903 Flora of the Southeastern US. In 1937, Munz reduced the species to varietal status as Oenothera tetragona ssp. glauca var. riparia, and after this it was essentially lost to the minds of taxonomists and plant enthusiasts being considered merely part of the immense variability of Oenothera fruticosa by Radford, Ahles and Bell (1968).
In the mid 1990’s while working in the tidal freshwater swamps and marshes of South Carolina, Richard Porcher and I encountered this species growing at the bases of Bald Cypress trees, on stumps, and on floating logs just above the high-water tidal line on the Waccamaw, Pee Dee, and Edisto Rivers. My frustration with its identification led me to the name Oenothera riparia and its recognition as a completely and consistently distinct taxon—which is very unusual in a genus known for its morphological variability and messy taxonomy.
This plant is smooth (lacking hairs) throughout with thick textured dark-green leaves and a very bushy habit—it does not produce long stolons or rhizomes, so it forms a dense clump. The stems generally range from a foot to nearly 3 feet in height and the thick stems become semi-woody, providing a stiffly upright growth form. Rather than a single burst of flowers this species produces masses of flowers over the entire summer (June-late August) with sporadic flowering later in the season.
Imagine, here we could have a sundrop that won’t spread like wildfire, doesn’t flop, and flowers for month after month! Sounds like everything you would want in a plant. There is only one problem, it hasn’t been cultivated. This is where the adventure continues and as we embark on this adventure, I would like to take you along for the ride. There is so much that goes into identifying a potentially great garden plant, evaluating it, and bringing it to the trade.
Our initial collections were made this August (2022) when Zac Hill, my wife Waynna, and I were traveling through the SC coastal plain. We made the stop at the Edisto River in Colleton County where I had seen the plant many years before and just like I remembered, there they were, full of seed and with some flowers still present. The only problem is that they were growing far out in the water along the bases of trees! The Edisto is a blackwater river with a large tidal amplitude at this location and it was full on high tide. If you’re a field botanist you forget entirely about the things that concern other more rational folks, like the multitude of large Alligators, and make for the plants. I found some low branches on a neighboring willow tree that kept my feet in only a couple feet of water, and balancing on the branch, in the water, made my way all the way to the edge of the river where a fabulous floating log provided an abundance of seeds and two small plants from a large cluster of individuals. The only casualty was my prescription glasses which promptly fell from my head into the depths of a rapidly moving Edisto River (my wife will not easily let me forget the cost of this single collection). The first step in the process of bringing a new plant into production is done.
Our two small divisions were placed directly into the sun garden at JLBG and the seed was sown. For this plant to be successful in a garden it must be able to not just survive but thrive in a common garden condition far away from its very narrow niche at the very upper edge of the water along the Edisto. You might think this would be unlikely, but other incredible garden plants are entirely found in wetland communities and thrive under very different conditions in the garden. A good example of this is found in another of our introductions, Eryngium ravenelii ‘Charleston Blues’, which comes from high pH wetlands not too far away from the Edisto River.
Will it be hardy here? Will it survive under normal garden conditions? Will it maintain its distinctive and garden-worthy features? Well at least part of this can be answered already. Our tiny divisions are now large overwintering basal rosettes. The plants have not thought about running away from their tight cluster, and they grew very well during their first autumn in soil that was not kept overly moist.
The real test lies ahead. What will the plants nature be under cultivation? Will it be as good as I think it could be? Will it be better? One can only hope, put in the labor, and follow along to find out the end of this story for Oenothera riparia. It could provide all of us with a stately and handsome bit of nostalgia with far greater design and utilitarian use for humans and our native biota. What’s more, there are other seemingly great garden-worthy Oenothera out there—not in far-flung locations but right here in the Carolinas. Have you ever heard of Oenothera tetragona var. fraseri? If not, look for us to tell you more about that in the years to come, there’s a fantastic form with huge flowers in the Blue Ridge escarpment of South Carolina!
While we leave all the fancy mangave creations to our friend Hans Hansen at Walters Gardens, we continue our work on creating more winter hardy (to 0 degrees F) hybrids. Over the last couple of years, we’ve made several crosses using some of Hans’ hardiest Agave ovatifolia based F1 generation selections, like xMangave ‘Blue Mammoth’ and xMangave ‘Falling Waters’ and crossing them back onto Agave ovatifolia.
The F1 mangave hybrids from Hans’ work, have all lost the monocarpic trait of pure agaves, meaning they will not die after flowering. We are curious what will happen if the hybrids have 2 parts agave and one part manfreda. With most of our crosses, we grow 100-200 of each into 1 qt pots, which allows us to do an initial culling after seeing the juvenile foliage traits.
The photos below are from that process, which happened this week. This is a cross of xMangave ‘Falling Waters’ x Agave ovatifolia ‘Frosty Blue’. The first image shows the diversity in the seedlings. All plants have some degree of glaucous foliage…some more toward blue and others with purple spotting that comes solely from the Manfreda parent. It was interesting that the F2 plants still showed some degree of purple spotting…probably around 5% of the plants.
From a batch of 100-200 plants, our goal is to select 10% for the next round of in ground trials. We focus on selecting at least one plant for each desirable trait. Those traits include: size (dwarf or large), leaf undulations, spotting density, best blue color, leaf twisting, leaf length, leaf width, overall form, best spination, and variegation.
Below are some of our final selections for the next phase of trials. These will be up-potted into 3 quart pots and overwintered indoors, since we’re already too late for planting outdoors this year. These will go into the ground in spring, after the danger of frost has passed.
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.
A couple of years ago, we made bi-generic crosses of the North American Manfreda maculosa and the naturally occurring hybrid Mexican tuberose, Polianthes x bundrantii ‘Mexican Firecracker’. These fascinating plants were still in full flower prior to our first hard freeze in the last few days. These are images of our top three clones, which we refer to as x Polifreda. Because we used the non-fragrant tuberose species, there is no noticeable aroma, but we opted for a much more diverse flower color range instead.
Hopefully, next year, we can use these to cross with agaves to create a new series of xHanseras. Pollen has been gathered and stored in the refrigerator in case bloom times don’t coincide next year.
I wish I could count how many times we’ve been told, “That won’t grow in your climate.”. Our contrarian streak has led us down many interesting paths, with quite a number of surprising results.
The most recent is Chrysophyllum oliviforme. Over a year ago, we planted seed grown plants, native to the recently hurricane-ravaged Sanibel Island, Florida. This species is native to Southern Florida, the Bahamas, the Greater Antilles, and Belize. With that distribution, it should have no chance in our winters, but, despite die back during last winter’s low of 16F, it returned, and is now approaching 4′ in height. I should add that our plant was planted on a very exposed site, with no protection.
Is it going to be a long-term plant….probably not, but there is obviously more winter hardiness than most informational sites would lead us to believe. I should add that we planted two seedling, and the other one planted nearby, succumbed to the winter temperatures. If you never take risks, you’ll rarely get to experience the joy of amazing surprises like these.
You go straight through to the round of botanical superstars if you recognize this little-known southeast native (SC to Florida), Piriqueta caroliniana. This Patrick McMillan collection from coastal SC has thrived all summer in our full sun rock garden, flowering constantly, with new flowers opening every other day. This oddity is a member of the Turneraceae family, which comprises nine other equally obscure genera. We’ve yet to determine if this will actually make a good garden plant, but evaluation continues. Hardiness north of Zone 8a is unknown.
We always look forward to elephant ear evaluation day at JLBG, which was recently completed.
Each year, Colocasia breeder, Dr. John Cho flies in from Hawaii to study and select from our field trials of his new hybrids. This year we were joined by Robert Bett, owner of the California-based plant marketing firm, PlantHaven, who handles the Royal Hawaiian elephant ear program. The JLBG trials consist of all named colocasia introductions growing alongside Dr. Cho’s new hybrids created the year prior.
JLBG staff members, Jeremy Schmidt and Zac Hill spent most of the morning working with Robert and John on the time-consuming evaluation process.
After lunch, Jim Putnam from Proven Winners, joined us to see which remaining plants struck his fancy for potential introduction into their branded program. As you can see, lots of amazing plants didn’t make the final cut, which is necessary, since we’ll need more room for the new selections.
Plants selected for introduction are then sent to a tissue culture lab to be produced for the next step, which is grower/retailer trials. If these are successful, and the plant can be multiplied well in the lab, the plants are scheduled for retail introduction.
Hopefully, by now, most folks are familiar with our 2020 top selection, Colocasia ‘Waikiki’, which hit the market this year. There are more really exciting new selections in the pipeline, but we can’t share photos of those quite yet…stay tuned.
We’re always on the search for new bananas that will be winter hardy without protection in our Zone 7b winters, and two that have looked great so far are the South Asian native Musa balbisiana (Northeast India to South China) and the Northeast Indian native Musa nagensium var. hongii. If these continue to thrive, we will propagate these so we can share.
We’ve just enjoyed peak surprise lily week at JLBG. The lycoris season starts for us in early July and continues into early October, but the last two weeks of August is peak bloom. Below are a few samples from the last few weeks.
The first two image are our field trials, where lycoris are studied, photographed, and evaluated for possible introduction.
There are only 6 lycoris species (despite what you read on-line). Four of these have foliage produced in spring, and two have foliage that emerges in fall.
Lycoris longituba is a spring-leafed species with flowers that range from white to pink, to yellow/orange.
Lycoris chinensis is a spring-leafed species with bright gold/orange-gold flowers. There is little variability in the color of this species.
Lycoris sprengeri, whose foliage emerges in spring, is the only pink flowered species, almost always with a blue petal tip.
Lycoris sanguinea is the fourth spring-leafed species, but one that performs quite poorly in our climate, and consequently rarely flowers for us.
Lycoris radiata is one of only two fall-leaved species. Lycoris radiata var. pumila is the fertile form, while Lycoriis radiata var. radiata is sterile and consequently never sets seed. There is little variability with regard to color, but there is great variability with regard to bloom time. Lycoris radiata is the earliest lycoris to flower in July and the last lycoris to flower in October.
Lycoris aurea is the only other fall-leaved species. In appearance, it is indistinguishable from the spring-leafed Lycoris chinensis, except that the foliage emerges six months earler.
Lycoris traubii is a hotly debated plant in taxonomic circles. Occurring only in Taiwan, some taxonomists insist on it being its own species, while other simply find it a form of the mainland Chinese Lycoris aurea…similar to the debate about Taiwan’s political status. Until we see other evidence, we view it as a form of Lycoris aurea.
All other lycoris are hybrids. Sadly, botanists continue to name new lycoris species, but after having grown each, we have yet to find any that are anything more than a previously named naturally occurring hybrid. Below are a few of the validly named hybrids.
Lycoris x albiflora is a group of naturally occurring crosses between the two fall-leafed species, Lycoris aurea and Lycoris radiata. Most emerge yellow and age to pink-blushed. If these hybrids cross back to the Lycoris radiata parent, the hybrids take on lovely orange shades.
Lycoris x caldwellii, named after the late Lycoris breeder, Sam Caldwell, is a hybrid between the spring-leafed species, Lycoris longituba and Lycoris chinensis.
Crosses between the fall-foliaged Lycoris radiata and the spring-leafed Lycoris sprengeri have been made more than any other interspecific lycoris cross. We currently grow over 200 clones of this hybrid, with flower colors that range from solid pink to bright red, and everything in between. Backcrosses onto one parent or the other influence the flower color expression.
Lycoris x rosensis is a hybrid between the fall-leafed hybrid above, Lycoris x rosea and the spring-leafed Lycoris chinensis.
Lycoris x sprengensis is a cross between the spring-leafed Lycoris sprengeri and the spring-leafed Lycoris chinensis. The flower buds almost all show a blue tip, whose color disappears as the flowers age.
Lycoris x straminea is very similar in appearance to Lycoris x albiflora. The only difference between the two is that one parent of Lycoris x straminea is the spring-leafed Lycoris chinensis instead of the fall-leafed Lycoris aurea. Interestingly, Lycoris x straminea is fertile, while Lycoris x albiflora is not. Because Lycoris x straminea is fertile, it can be crossed back onto its Lycoris radiata parent, created some stunning orange-hued flowers
Most Lycoris x straminea clones open pure yellow, and acquire a reddish-orange blush as they age, from the Lycoris radiata parent. You can see an example below with two images taken 2 days apart.
Lycoris ‘Peppermint’ is an old passalong hybrid of two spring-flowered species, known and sold as Lycoris x incarnata…a cross of Lycoris longituba and Lycoris sprengeri. Our studies, however have shown that this plant could not have arisen from such a cross. In hybrids between a spring and fall-leafed species, the offspring always has foliage that emerges in early fall (September, October). The foliage on this emerges in late November, and the only way this could happen if the hybrid included 2 spring species and 1 fall species.
The only species that could provide the red color is the fall-foliage Lycoris radiata and the only species which could contribute the white color is Lycoris longituba. The other parent must be a spring-foliage species, so the only option is Lycoris sprengeri. We now feel confident that this hybrid could only have occurred with a cross of Lycoris sprengeri x radiata x longituba. We call these hybrids, Lycoris x longitosea (longituba x rosea).
To determine which lycoris will thrive in your hardiness zone, simply look at when the foliage emerges. The fall-foliage species/hybrid are best from Zone 7b and south, although some will grow in Zone 7a. The spring-foliaged species/hybrids should be fine in Zone 5, and possibly as far north as Zone 3.
While lycoris will grow and flower in sun, they perform far better in filtered deciduous shade, where the foliage will have some protection from the ravages of winter. The amount of light they receive in summer when they have no foliage isn’t really relevant to their performance.
Gardeners in Zone 7b wouldn’t typically think of Angola (tropical West Central Africa) as a place to search for hardy perennials, but we’ve been thrilled with the performance of two natives of the region, Crinum fimbriatulum and Crinum jagus. The reason we kill so many plants is we try things that people with better sense would assume wouldn’t have a chance of the proverbial snowball.
Crinum fimbriatulum is flowering now for us, while Crinum jagus bloomed a few weeks earlier. Crinum fimbriatulum is the taller of the two, with spikes reaching nearly 4′ tall. Our plants were planted in 2009. They thrive in average to above average soil moisture.
Crinum jagus has been in the ground at JLBG since 2015. It’s a much shorter plant with 2′ tall flower spikes, but with incredibly lush, attractive foliage.
Just back from the Perennial Plant Association meeting in Lancaster, PA, held in person for the first time in three years. It was like a family reunion after such a long period of no contact, except via Zoom. Over 450 people from around the world showed up for the first year back.
The Perennial Plant Association is a professional organization for people involved in production, sales, trials, research, landscaping, or growing perennials. The annual meetings consist of a week of talks, tours, and a trade show. There are plenty of tour options, so attendees can select whether they are more interested in landscape design, retail, or production.
Aris Greenleaf is a large liner producer, who also has a trial garden. Sadly, non of the trial plants here had been planted more than a few months.
Cavano’s Nursery in nearby Maryland, was one of several top notch perennial growers we visited.
North Creek Nursery, a leading producer of native plant liners in PA, hosted the group for an amazing dinner
Owner Ed Snodgrass welcomed the group to his Emory Knoll Farms, an “off the grid” nursery that only produces plants for green roofs. 100% of their power is produced by solar panels on site.
For those unfamiliar with green roofs, shingles are replaced with plants, which help insulate the structure, while also reducing runoff.
What interested many on this tour, was their use of an outdoor version of a Stanley Steamer, for weed control. The manufacturer, Weedtechnics is out of Australia, but has a few US distributors.
Steam is applied too kill weeds as you would clean a carpet. The steam only penetrates the ground to 5 mm, but that’s enough to kill both the weed and weed seed, without bothering nearby plants. This is certainly a technology many of us on the tour will be investigating.
We visited the amazing Mt. Cuba Center in Delaware, a place I’ve had the pleasure of visiting several times over the last 30 years. The gardens have undergrown a dramatic facelift that made a great garden even better. It was great to catch the native Zigadenus glaberrimus in full flower by the lower pond.
The amazing Chanticleer Gardens and Longwood Gardens both hosted the group for two incredible dinners and a chance to stroll the grounds. At Chanticleer, we caught the water lotus (Nelumbo) in full flower, looking eerily like something from the Little Shop of Horrors.
Of course, we are all there to see the latest and greatest in new plants, and these gatherings never fail to show us something new we need to try. Below are the latest from the world of echinacea breeding.
Of course, in addition to the plants, these meetings are also about the people and the networking that these meetings afford. It was great to see two former JLBG’ers in attendance, Adrienne and Jon Roethling. Adrienne is now the Director of the Paul Ciener Garden in NC, and Jon heads up the grounds at Reynolda House and Gardens.
It was a lovely surprise to run into an old friend, plantsman Barry Yinger, who was in town, taking a break from his Sanseveria conservation work in Tanzania to visit his sister, and happened to be staying next door to the convention.
It’s always great to catch up with old friends, Nanci Allen (long time PPA director), and Allan Armitage (retired UGA professor). You never know who you’ll run into at these meetings. If you work in the field, check out the PPA, and perhaps we’ll see you at a future symposium.
Flowering now in the rock garden is the European native, Anthyllis coccinea…aka: red kidney vetch. This small rock garden legume (Fabaceae) is still in its first full year in the ground, having been planted last June…so far, so good.
Okay…everyone raise your hand if you’ve grown Mytilaria laosensis. This odd monotypic genus, native from Southern China to Laos, is first cousin to the also virtually unknown genus Exbucklandia, both in the Witch Hazel family, Hamamelidaceae . Since we’ve had our Exbucklandia in the ground since 1997, we though it was worth trying its cousin.
Our Mytilaria is Dan Hinkley’s collection from Huanan…probably the first accession in the country. Dan has actually never put one in the ground and told me that it would certainly die when we hit 27F. Well, we’ve dropped to 25 so far, and it still looks great, so we’ve already pushed the envelope. We truly have no idea what temperatures it will take, but that’s why we trial plants. As the late JC Raulston used to say, “Unless you’re killing plants, you’re not growing as a gardener.”
Because we’ve had three consecutive mild winters, we’ve had some survivors that probably wouldn’t have made it through a normal winter. One of those plants is Callistemon viminalis ‘Light Show’, which is looking really superb this fall. Perhaps this year, we’ll get back to our more normal winter low temperatures of 5-10F, but in the meantime, we’ll enjoy these amazing trial plants.
Apologies for commandeering the famed Duke Ellington line, but it seems appropriate for the new Colocasia ‘Waikiki’.
When we first met Hawaii’s John Cho in 2003, we knew some special elephant ears would be the result of our collaboration, but it was hard to imagine something like the seriously tricked-out Colocasia ‘Waikiki’. Almost every year, John, who has now retired, but is still actively breeding elephant ears, travels to JLBG to evaluate his new hybrids at our in-ground trials and make future introduction decisions. There are some seriously amazing new selections starting down the introduction pipeline.
Colocasia ‘Waikiki’ will be released from Plant Delights Nursery on January 1, so if you like this, mark you calendars and stay tuned to the website.
We trial several hundred newly developed plants each year, and most never grace the pages of a PDN catalog, either because of performance or a lack of uniqueness. One that has fascinated us is Dahlia ‘Grandalia Burgundy Improved’. With a height and spread of 20″, you’d swear that this dahlia had either been regularly clipped or sprayed with growth regulators, neither of which are the case. The gem has been looking quite incredible in the garden, as it moves into its third year of trial. Obviously, it’s a perennial here in Zone 7b, but would be tender farther north. We’d love to hear your thoughts..