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 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.
Gardeners typically curse fall leaf drop, but ginkgo trees often get a pass, not only because the golden fall leaves look so great on the tree, but they also look great on the ground, not displaying the disheveled look of other larger tree leaves. Here’s our ginkgo tree, planted just in front of our office, that’s been putting on quite a show for the last few weeks.
Despite what most folks think, the genus Ginkgo is indeed a North American native, but to understand that, requires a bandwidth that many native plant purists simply don’t have. Native is not a place in location, it is only a place in time. The first Ginkgos date back to the lower Jurassic period about 190 million years ago, when the genus was born in Mongolia. From there, it migrated around the world, based on dramatic climate change, with fossils found from what is now the UK to the US (Oregon to North Dakota).
Ginkgos continued to diversify through the Cretaceous period (65-145 million years ago), when they reached their maximum distribution, with 5-6 species currently recognized. By the Paleocene (56-66 million years ago), all of the species but one had gone extinct. Although that remaining species is known as Ginkgo adiantoides, it is almost identical to today’s Ginkgo biloba.
During the Oligocene (23-34 million years ago), Ginkgos moved south from their more northerly range, with the genus completely disappearing from North America around 7 million years ago. According to the fossil records, Ginkgos subsequently disappeared from Europe around 2.5 million years ago. The only vestiges of the genus that remained, holed up in three distinct refugia (botanical hideouts) in China until humans began to spread them out again and re-populate the rest of the now Ginkgo-less world. They returned to the Flora of both North America and Europe in the 1700s.
For those who want to dive deeper into the Ginkgo story, here is a link and another.
Last weekend, we were thrilled to host a bus tour from the International Maple Society, that was meeting in North Carolina. As you can imagine, it was fascinating to walk the gardens with such an amazing and diverse group from around the world. Here are a few of our visitors: Tim (l) and Matt (r) Nichols of Mr. Maple Nursery in NC. The Nichols brothers have set the woody plant world on fire with their amazing mail order nursery, based out of the Asheville area. Maples aren’t their only focus, but there hasn’t been a woody plant mail order nursery in my lifetime to do such a great job with both selection and customer service as the Nichols brothers.
Sandwiched in between them are Haruko and Talon Buchholz of Buchholz Nursery. Talon has long been one of my horticulture idols, and I’ve been blessed to have visited their nursery twice during the last 30 years. Although Talon has visited JLBG once prior, this was my first time to meet his amazing wife, Haruko. Like Mr. Maple, Buchholz Nursery in Oregon focuses on maples and conifers, but unlike Mr. Maple, Buchholz is strictly wholesale.
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.
If you’re like us, you never have enough purple-foliage plants in your landscape, so we’re always on the lookout for something new. One of our finds a few years back is this purple-leaf plum from our friend Dr. Dave Creech in Texas. Prunus ‘Purple Pride’, which Dave and his staff at Stephen F. Austin State University discovered, is a seedling of the widespread native, Chickasaw plum, Prunus angustifolia, with an unknown suitor.
Many purple-leaf trees loose their color during the summer, but not Prunus ‘Purple Pride’. Our specimen at JLBG, pictured below is 4 years old. We have also not seen any sign of diseases, which often plague many domesticated prunus. This should top out around 12′ in height and 15′ in width. Supposedly, our tree will fruit eventually, and reportedly, the fruit are rather tasty. Hardiness is Zone 7a and warmer.
Betula nigra ‘Summer Cascade’ is a selection of our native river birch from our friends at Shiloh Nursery in NC, that I can’t imagine gardening without. This is our 19 year old specimen looking absolutely fabulous this week. The plant patent expired last week, so now this amazing plant can be propagated by anyone. Hardiness is Zone 4b-9b.
We’ve had a longstanding love affair with the genus styrax, thanks to their amazing spring display of fragrant white bell-like flowers. Of the 130 recognized species, we have so far tried 22, of which 9 remain alive.
The first featured below is Styrax japonicus ‘Evening Light’. This amazing, black-foliage form of the typical green-leaf Styrax japonicus appeared as a seedling in Holland at the nursery of Henny Kolster. When I first saw the photo, I assumed it to have been “photoshopped”, but after growing it for several years here at JLBG, the foliage is indeed jet black. This is one of the most stunning small trees in our collection.
Styrax formosanus, which hails from Taiwan (Formosa) is undoubtedly the most floriferous species we’ve encounterd. Here is our garden plant this spring. For us, this generally tops out at 15′ to 20′ tall.
Styrax americanus (Illinois south to Florida) is one of only four native US styrax species. Usually topping out around 10′ tall, this form introduced by Woodlanders Nursery has foliage with a lovely blue cast.
We’ll certainly remember 2022 for many reasons, but a highlight is the first flowering of our Davidia involucrata ‘Sonoma’. This incredible tree was named for French missionary and naturalist, Armand “Pere” David (1826-1900), who first discovered the tree in its native China.
Like dogwoods, what we think of as flowers are actually bracts, the effect is that of the tree in flower is like a dogwood on steroids. Interesting, davidia is in the black gum family, Nyssaceae, and although this tree is not common, it has acquired the common name of dove tree.
We’ve learned a bit about what davidia likes, having killed five plants since first trying it in 2002. Full sun is not ideal, as is deep shade. Our original plant, which as been in the ground since 2002 has yet to flower. The plant of Davidia ‘Sonoma’, which flowered this year, was planted in 2014, and is thriving in light shade/part sun.
Flowering in our parking lot now is the beautiful Halesia diptera var. magniflora, better known as big-flowered two-wing Silverbell. Native from Georgia across to Texas, this beautiful small tree can be found in low moist woodlands. That said, it thrives in average to dry garden conditions.
The variety “magniflora’ is distinguished from the more northern Halesia diptera var. diptera in that the gulf coast form has much larger flowers. This is our collection from Wilcox County, Alabama, where the foliage is much wider than what is typically seen in this taxa. Plants mature at around 20′ in height. Hardiness is Zone 5-8.
This winter has been an amazing one at JLBG for the mid-winter flowering, evergreen magnolias. Formerly known as Michelia, there are several species from warm temperature Asian climates, which flower in the mid-winter. The plant in the top photo is our oldest specimen of Magnolia platypetala, and below is Magnolia macclurei…both planted in 1999, and in full flower in January. Obviously, we will loose open flowers if winter night temperatures drop too far below freezing, but the remainder of the flower buds usually open shortly after temperatures warm.
Also, the bright gold shrub in the first image is the original plant of our introduction, Illicium parviflorum ‘Florida Sunshine’…the plant from which all plants in the world were propagated. To the lower right is the Mediterranean native, Phlomis fruticosa ‘Miss Grace’. All in all, a lovely winter garden combination.
I remember falling in love with the dwarf river birch, Betula nigra ‘Little King’, back around 1990 when it was first planted at the JC Raulston Arboretum in Raleigh, NC. This amazing compact selection originated in the late 1970s at King Nursery in Oswego, Illinois, and starting in 1991, was adopted and formally marketed through the Chicagoland Grows plant introduction program.
After 20 years, the original plant in Illinois was only 10′ tall, but the 30 year old specimen at the JC Raulston Arboretum has now reached 30′ tall x 30′ wide So, while it is much slower growing, it’s not exactly a true dwarf. Most estimates conclude that Betula ‘Little King’ will grow about 1/3 to 1/4 the speed and size of the typical species, making it a much better choice around most smaller homes. That said, we love the compact, dense habit and have recently planted this specimen around our home on the JLBG property. Hardiness is Zone 4-9.
It’s far more common for new perennials to be discovered than new trees…it’s a size thing. Botanists were excited in 1960, when Chinese professor H.T. Chang published a new small tree that he thought to be a witch hazel, named Hamamelis subaequalis. The original Jiangsu Province collection actually dated to 1935, but it took 25 years to be published based on a herbarium specimen of the fruit.
The new hazel hadn’t been seen alive since 1935, and was assumed extinct, when it was rediscovered in 1988 by a team from the Jiangsu Institute of Botany. After studying live flowering specimens for three years, it became obvious that It wasn’t a witch hazel at all, and a new genus, Shaniodendron was published for the plant. Here, it remained, until 1997, when DNA analysis revealed that Shaniodendron was actually a second species in the formerly monotypic genus Parrotia….only living some 3,500 miles from its nearest relative. Its sibling is the famed Iranian Ironwood (Parrotia persica).
Currently, there are only five known populations in China, so it is quite rare in the wild. The largest plants seen in the wild were 30′ tall, but Parrotia subaequalis should grow slightly taller in cultivation. The photo below is our 13 year old specimen. Most plants of Parrotia subaequalis in the US, including our specimen pictured below, trace back to famed Japanese plant collector of Chinese plants, Mikinori Ogisu. Fortunately, Parrotia subaequalis is quite easy to root from cuttings, so we hope its not long before this amazing plant becomes much more widespread in commerce. In trials so far, it came through -25 degrees F with only slight tip damage, so it looks like a solid Zone 5-8 plant.
Back in 2010, Plant Delights made a limited offering of a hybrid monkey puzzle tree…a cross of Araucaria araucana x angustifolia, which we hoped would have the hardiness of A. araucana and the moisture tolerance of A. angustifolia. Well, a decade later, here is the result…exactly what we’ve hoped for. Our tree is now about 45′ tall.
Sadly, no seed has ever been available again, but our tree is finally coning, as is its sister, growing at the JC Raulston Arboretum. Fingers crossed that we get seed set and can off this gem again.
Outside of the nerdy members of the International Oak Society, few gardeners have ever heard of Quercus x vilmoriniana. This spectacular oak is a hybrid between the Asian Quercus dentata and the European Quercus petraea. Quercus x vilmoriniana has been known in European gardens since 1894, but is rarely seen in US gardens. The hybrid is named for the late French botanist Maurice Leveque de Vilmorin.
Our 20′ tall specimen at JLBG was planted in 2012 and has developed not only superb foliage, but splendid deeply-fissured bark. There is an old specimen at Cornell in NY, so it shows good cold tolerance in addition to loving our hot, sweaty summers. We have sown acorns from our plant, and if they grow, we will make this available though the Southeastern Plant Symposium Rare Plant Auction in June.