Slightly Deranged Hydrangeas

We love the genus hydrangea, but are really fascinated by those at the far end of the family tree. While most hydrangeas flower in late spring, we actually have a couple flowering now we’d like to share.

The first is Hydrangea involucrata, a native to both Japan and Taiwan. The word “involucrata” indicates it has some serious involucres (the bracts surrounding the inflorescence). The first image shows the plant in bud, the second in full flower, and the third image is after the flower color has faded. All three stages are on display at once in the garden this week. They typically reach 6′ in height and width. Winter hardiness is Zone 6a-8b.

Hydrangea involucrata in bud
Hydrangea involucrata

Hydrangea involucrata

Hydrangea amamiohshimensis (below), from Japan’s southern Ryuku Islands, was once considered a hydrangea cousin, until a 23andMe test confirmed it was actually a true hydrangea. Prior to the test, it belonged to the genus cardiandra, which was effectively a perennial hydrangea, dying back to the ground each fall like most perennials. It too is in full flower in the woodland garden this week. Perhaps now that it has a recognizable name, more folks will be willing to grow it. This is the only one of the four former cardiandra species that has survived in our climate.

Hydrangea amamiohshimensis

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.

Miscanthus transmorrisonensis

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.

Meet Jack from Ilan

Flowering at JLBG since early March is the little-known Jack-in-the-pulpit, Arisaema ilanense. This collection hails from Ilan (Yilan), in northeastern Taiwan, and for us is the very first arisaema to flower each winter, even when temperatures are still quite cold. The mature size is only 4-6″ in height, so this is one for a very special site in the rock garden. There are very few plants of this species in ex-situ conservation collections, so thanks to JCRA Director, Mark Weathington for sharing. Our specimen has been in the garden since 2016. Hardiness is unknown, but we’re guessing Zone 7b-9b.