We’ve played around with growing cast iron plants from seed, curious if the white-tipped pattern of Aspidistra elatior ‘Asahi’ was heritable. Turns out that it is. Aspidistra ‘Blizzard’ is our seedling with well over half of the leaf being white. That makes it both beautiful, but insanely slow growing. The plant below has been in the ground for 5 years, planted as a two year old seedling.
We grow quite a few sarracenia (pitcher plants) from seed, with only the very best (most unique and most vigorous) getting planted in the ground for further trials. Through the decades, we’ve only had a few that we eventually found worthy of a name. Below is a photo taken this week of a newly selected Sarracenia purpurea hybrid, that we’ve named Sarracenia ‘Fire Chief’. This almost certainly has genes from Sarracenia leucophylla. Later this year, we’ll chop into the plant to start propagation, so we can share.
Looking great in mid August is Hedychium spicatum. This is a ginger lily species we saw throughout our late 1990s travels in Yunnan, China. Pictured below are our 3 year old seed-grown specimen, which has already become a massive 5′ tall x 10′ wide. The flower is much smaller than some of the more showy species of hedychium, but the overall garden impact is quite grand. Hardiness is Zone 7b-10 (guessing).
As we mentioned in a recent blog, we have a ridiculously large collection of Crinum lily cultivars and species. Despite this, we’re always making new crosses in our goal to improve the quality of plants available. Despite their being nearly 1,000 named crinums, there is still dramatic room for improvement. Below is one of our seedlings, which we named last year (Crinum ‘Americana’), erupting in a blaze of glory last week. Most crinum lilies flower for a period of 1-2 months with little to no care, so there’s good value for the space taken. Since the bulbs are so large, it will usually take years to produce and propagate enough of a new introduction to share with the public.
Here’s another of those plants that virtually no one has either grown or even knows about. Handelia trichophylla is a little-known monotypic member of the aster family (Asteraceae). Not only does it have hairy, silver foliage, which usually spells certain death in our summers, but it hails from the “stans”, which include the low rainfall countries of Afghanistan, Kazakhstan, Kirgizstan, Pakistan, Tadzhikistan, Turkmenistan, Uzbekistan, and Xinjiang. Our particular plant is from a seed collection in Tadzhikistan.
We would not typically expect anything native to the “stans” to survive in the hot, humid Southeastern US, but this is why we experiment, and why we create unique habitats and microclimates in our garden. In this case, Handelia has thrived for four years in our crevice garden, where it grows in a soil mix of 50% Permatill.
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.
In the crinum lily world, a yellow flower is considered the holy grail by plant breeders, since it only naturally exists in the Australian crinum species, Crinum luteolum. Two other species which occasionally show a yellow blush in the flower are Crinum bulbispermum and Crinum jagus. Crinum luteolum is completely ungrowable in the Southeast US. Consequently, we must find yellow pigment from the other two species.
Many years ago, a secretive California crinum breeder distributed a fuzzy Sasquatch-like photo of what was supposedly his yellow flowered crinum, derived from a white-flowered Crinum bulbispermum. The plant itself has never been seen in person, despite assurances from the breeder that it still exists. In 2008, the breeder agreed to sell us seed from his parent plant, with the caveat that it wouldn’t look like the parent.
Below is the best clone that we selected from our first set of seedlings from Crinum ‘Yellow Triumph’. As you can see, the flower is virtually all white, except for a chartreuse green base. Since it was a nice flowering clone, we gave it the name Crinum ‘White Swans’.
Since 2008, we have repeatedly self-pollinated our original seedling selection, each time selecting those offspring that showed the most yellow color. Over time, the best seedlings were crossed with each other, and the selection process continued.
Fast forward to 2023…15 years after our original seedling flowered, we finally have plants that are showing a decent amount of yellow in the flowers. The yellow shows best as the flowers open in late afternoon. Below are two of our best 2019/2020 seedlings. While these aren’t yet a finished product, we are seeing the proverbial gold light at the end of the long tunnel.
This is the third year we’ve seen our seed grown, double-flowered Paeonia ostil flower, so we’ve now christened it Paeonia ‘Body Double’. We’ve grown many hundred Paeonia ostii from seed, and this is the first that’s shown any tendency toward double flowers. Most tree peonies are propagated by grafting or tissue culture, so we’ll need to find someone that’s up to the task, before we’re able to share. Hardiness Zone 4a-8b.
Flowering now is the Federally Endangered hardy cactus, Escobaria minnima. Our plants are now almost five years old from seed. We are thrilled to see that these have performed so well, sailing through our 11 degree F. winter this year. This extremely rare gem (G1 rank) is only found a single rock outcrop in Brewster County, Texas, hence it was added to the Endangered Species list in 1979. (Hardiness Zone 5b-9b).
A couple of years ago, we were thrilled to acquire seed of Euphorbia ‘Rubicund’ from the Hardy Plant Society seed exchange. That little-known clone is a selection from a cross of Euphorbia myrsinites x E. rigida made by Rhode Island’s Issima Nursery. While the clone doesn’t come true from seed, we love our offspring and look forward to seeing what our seed crop from the plant below will have in store.
For this hybrid, we’ve settled on the nothospecific name E. x myrsida, going forward. Over 15 years ago, we acquired a similar cross from California salvia guru, Betsy Clebsch, but we unfortunately let our plant get shaded out. Both plants we’ve grown of this cross produced much larger seed heads with a form similar to both parents. It has been stunning in our our rock garden for the last month. Hardiness is probably Zone 6a-8b.
Looking lovely in our parking lot this week is the Southeast US native, Halesia diptera var. magniflora ‘Pine Apple’. This is a seed strain we named from a 2011 collection in Wilcox County, Alabama. Hardiness is Zone 5b-9a, at least.
The horticultural world just lost another stalwart with the passing of plantswoman, Sally Walker, 87, of Southwestern Native Seed. After departing her native England, by way of New Zealand, and later California, Sally and her husband Tim, settled in Arizona in the 1960s. After working for several renown nurseries in both the UK and US, she started her own seed company, based out of Tucson in 1975, which would become Southwestern Native Seed.
Over the next 32 years, Sally was one of the only sources of many southwestern native plants, introducing several great new plants to commerce including Agastache rupestris, Penstemon cardinalis, and Aquilegia desertorum. Her relentless travel schedule took her throughout the Southwestern US and into the mountains of Northern Mexico first to find and study the plants and then return a second time for seed.
I would always drop what I was doing when Sally’s catalog, filled with her own plant sketches, arrived.
We were fortunate to have Sally visit JLBG several times, and below is an image from her 2009 trip.
If you’ve driven through the any of the Mediterranean countries in spring, you are undoubtedly familiar with the common Mediterranean spurge, Euphorbia characias (ker-ack-iss). For years, I admired this in virtually every English garden book, but always failed in my attempts to keep it alive in our garden.
Years later, it finally hit me what I was doing wrong. Euphorbia characias is a short-lived perennial – think 3-4 years max. I was purchasing clonal selections and expecting them to last, while not providing an environment where they would be prone to reseeding, which ensures that you actually keep the plant around. Despite needing to reseed to survive, it’s not a plant that’s prone to getting out of hand.
Euphorbia characias like dry, well-drained soils, especially those that are gravelly. We have also discovered that rich, amended beds also allow for reseeding as long as aren’t heavily irrigated. Now, we allow the seed heads to remain until the seed have dropped, at which time they are cut back to the blue foliage. We have found that leaving the seed heads on the plant too long actually shortens the plants already short lifespan.
Not only is Euphorbia characias an incredible ornamental, but it also has the longest duration of use in Western medicine. Recent research has found the plant to have a wide array of medicinal compounds. These compounds have activity as antioxidants, as pesticides (both anti-viral and anti-microbial), as wound healers, to treat hypoglycemia, as an anti-aging agent (preventing free radical chain reactions), and as a disease (HIV) enzyme inhibitor. I’d say, that’s a pretty impressive resume. Hardiness is Zone 7a-10b.
Here are a couple of dwarf pines in garden that are looking particularly great in mid-winter.
The first is PInus strobus ‘Mini Twists’ is a dwarf seed-grown selection of our native white pine that matures at 6′ tall x 4′ wide. This is a 2005 introduction from Vermont conifer specialist, Greg Williams. Good drainage is a key to success with white pines in our hot, humid climate. Hardiness is Zone 3a-8a.
Below is Pinus thunbergii ‘Thunderhead’, a 1987 introduction of a selected seedling of Japanese black pine from Angelica Nurseries of Maryland. In 10 years, it reportedly will reach 15′ in height x 20′ in width. Although it’s known commercially as Pinus ‘Thunderhead’, that cultivar name was actually used six years prior for a different pine, and according to International nomenclatural rules, can only be used once per genus, so the correct name would become Pinus ‘Angelica’s Thunderhead’. Hardiness is Zone 6a-8b.
We have been very impressed with the very narrow selection of our East Coast native arborviatae, Thuja occidentalis ‘Brobeck’s Tower’. This has been in the garden now for 4 years, and is 6′ in height and just over 1′ in width. This seedling selection was made by Sweeden’s Anders Brobeck, where the same plant takes 20 years to reach this height, due to a lack of summer heat.
We were thrilled to see most of our plants of Trichocereus ‘Love Child’ come through the 11 degrees F unscathed. We hope to have enough of these in the next year or two to share. We had long wanted to grow and offer some of the ridiculously large flowered, tacky colored tropical trichocereus cactus, but they simply had no winter hardiness.
Enter our former volunteer curator, Mike Papay, who had the same idea, but was more determined to make it happen. Mike worked with Trichocereus bruchii, and the resulting second generation plants yielded one he named Trichocereus ‘Big Time’.
He created another winter hardy hybrid using Trichocereus bruchii and Trichocereus thelogonus that he named Trichocereus ‘Iridescent Watermelon’. We subsequently crossed both of Mike’s hybrids together to create a seed strain we named Trichocereus ‘Love Child’. Below is one of our garden plants after enduring 11 degrees F. Below that is the same plant in flower last spring. Hardiness zone 7b to 10b.
In 2006, NC plantsman, and our long time customer, Graham Ray of Greensboro, emailed to see if we were interested in a dwarf Asaparagus densiflorus (Sprengeri) fern that he grew in his rock garden, and had been winter hardy for several years in his Zone 7a garden.
We had already worked with several asparagus species for years, and have a great fondness for the ornamental potential of the genus, so of course, we jumped at the opportunity. We were perplexed, however, how a dwarf version of the marginally hardy Asparagus densiflorus could have survived in Greensboro, which is a 1/2 zone colder than our garden south of Raleigh.
Despite our skepticism, we planted our new treasure in fall 2006, which thrived here, despite our winter hardiness concerns, not blinking during three upcoming single digit F winters. A few years later, we sent a plant to our friend Hans Hansen at Walters Gardens in Michigan for further testing. Despite their winter temperatures well below 0F with no snow cover, it thrived there also. What was going on, we wondered, since this simply shouldn’t be possible.
Our mystery was finally resolved this summer when taxonomy researchers from the University of Georgia, working on the phylogeny of the genus Asparagus, learned of our extensive collection of Asparagus species, and came by to take samples for their research. This fall, we got word that our dwarf plant which we had named Asparagus ‘Graham’s Cracker’, was in fact not a selection of the common hanging basket species, Asparagus densiflorus, but was instead a seedling of the Zone 4 hardy Asparagus cochinchinensis.
As we re-traced the plants origin, it turned out that Graham had purchased the plant here at Plant Delights, as a dwarf seedling he found in one of our sale house flats, which our staff had failed to notice.
Above is a photo of a mature plant of Asparagus ‘Graham’s Cracker’ at JLBG, which has finally reached a whopping 15″ in height…a perfect plant for the rock garden or in larger bedding schemes. Like the species, the fall foliage is a brilliant gold.
And here’s mama, Asparagus cochinchinensis ‘Chuwang’.
We have been fascinated with hardy cyclamen since the 1960s, but in recent years have spent a bit of time isolating some of the best silver-leaf variants that showed up in our seed pots and getting these established in the garden. These silver leaf oddities can be found in the wild, although they are fairly rare. In cultivation, however, they come fairly true (50%) from seed.
Through Plant Delights, we offer these as seed strain cultivars, under the names below…when available. A new crop of cyclamen will go on-line January 1, and there are some real beauties. Here are some images from the garden this week. Winter hardiness is Zone 4a-8b.
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.
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.
I wonder if the late Atlanta nurseryman, W.L. Monroe had any idea what would become of his white-flowered monkey grass, that he selected as a seedling and subsequently introduced to the gardening world in 1957?
In the 65 years that’s passed since it’s introduction, Liriope muscari ‘Monroe White’ is still the gold standard by which all white-flowered liriope are judged. Here are our plants flowering this week at JLBG. Unlike most liriope, which thrive in sun, this cultivar needs light shade for most of the day to prevent foliar scorch. Our plants in the photo only get a couple of hours of direct sun, where they thrive. Winter hardiness is Zone 6a-10b.
We’ve long had an affinity for larches (probably due to a hangover from watching the Monty Python larch skit far too many times), but there aren’t many larches that will survive our hot, humid summers. We can, however, succeed with the false larch, which belongs to the monotypic genus, Pseudolarix. Both larix (larch) and pseuodlarix (false larch) are deciduous conifers, whose foliage turns golden yellow in fall prior to leaf fall.
Pseudolarix is known as an open, airy species, and having seen quite a few over the last 50 years, all were very similar. Imagine our surprise, when a new seedling we purchased in 2017 turned out to be incredibly dense and fast growing. The first photo is our oldest typical pseudolarix, now celebrating 29 years in the garden.
The new clone, which we’ve named Pseudolarix ‘Greensanity’, just 5 years in the garden, is pictured below that. We look forward to working with some woody plant nurseries to get this exceptional form grafted and into the trade.
This spring, one of our flats of Rohdea japonica seedlings turned up with an inordinate number of variegated seedlings. In a flat of approximately 1,000 seedlings, we typically expect 3 – 10 variegated offspring, when the parent plant has white streaking in the middle of the leaf (L2 layer).
All of the variegated seedlings were removed and potted individually last week…all 300 of them. It will be fascinating to see what unique forms result.
One of our Paeonia ostii seedlings flowered well for the first time this year, and turned out to be semi-double flower instead of the typical single flowers. We’ll continue to observe it in future years and make sure the trait is stable, but if so, this could be a lovely addition to the world of hardy tree peonies that tolerate heat as well as cold.