Fall colors are slowly emerging from summer’s greenery. The many ripening berries, deepening oxblood-to-burgundy beetlebung trees, and festoons of gypsy scarlet Virginia creeper do point the way to elusive winter. True to late 20th and early 21st-century trends, Island summer and autumn extend into a never-ending season, lulling many into believing, for a minute or two anyway, that winter will never come.
Plants with the attribute of late garden color are few. One of these is lespedeza, in the Fabaceae, known also as bush clover or bush-pea. Somewhere between a shrub and an herbaceous perennial, lespedeza may be seen at Polly Hill Arboretum cascading over the front fence.
I knew the name but had not actually seen plants until some years ago at the Arnold Arboretum. I remained unimpressed. I knew it was of Asiatic origin, a pollinator attractor, erosion control plant, and potentially invasive. However, it was only when I became familiar with lespedeza’s deer and drought tolerance and season-extending color that I became a committed fan. More Island gardeners are now joining in the discovery.
Armitage and Dirr both describe lespedeza as having two garden-worthy species: L. thunbergii and L. bicolor. Cultivars of thunbergii to look for include white Alba (Albiflora), White Fountain, rosy pink Pink Cascade, Gibraltar, and L. liukiuensis syn L. thunbergii subsp thunbergii Little Volcano. Cultivars of bicolor include Little Buddy and Yakushima, both pink. These are big plants; 5-feet-tall by 6-feet-wide; bloom on new wood; cut to the ground in early spring.
Dehisce & abscise
In my haste to meet an early deadline and failing to check my copy properly, I misused “dehisce” for “abscise.” (Garden Notes, 14 Oct.) Turns out, these botanical terms are a good lead-in to describe autumnal phenomena, in both gardens and larger landscapes.
Deciduous leaves “abscise” and fall in autumn. Dehiscence occurs when certain plants’ ripened fruits or seed pods “dehisce” and split open. Milkweed pods dehisce, a sight familiar to most.
Leaf abscission is the normal shedding that occurs during autumn of an old leaf at the base of the petiole.
Some plants may even eject their dehiscent seeds as far as possible from mother plants to disperse their progeny. As I write, I am waiting for the witch hazel near the kitchen porch to explode its seeds from its dehiscing capsules. A loud “ping” or “pop” means seeds have hit the window or grill nearby.
Although I planted the witch hazel here in a dry site, where it seems very happy, native Hamamelis virginiana is found growing in damp, up-Island woodland areas of Martha’s Vineyard. Look for it in the Waskosim’s Rock Land Bank preserve.
Witch hazel is just coming into bloom now, with spidery, pale yellow, slightly fragrant flowers clustering close onto spreading branches, and leaves turning a nice yellow. Selected witch hazel cultivars have been chosen to bloom after leaves abscise, for better flower viewing. Mine is a straight species though, mingling foliage and flowers. It sustains late-season insects, which will pollinate it, forming those explosively dehiscing seed capsules.
Hops for screening?
As a fan of hoppy brews, I enjoyed reading Lucas Thors’ recent MV Times piece about Island hops gardeners and their harvesting methods and camaraderie. As a fan of beautiful plants, I appreciate hops (Humulus lupulus): tall-growing plants with decoratively formed foliage and papery flowers that resemble small pinecones.
The article explained that the hops plants are known as bines, not vines, due to their climbing habit which is based on twining (bines), not tendrils (vines). Climbing vines and bines are useful for privacy screening. Shouldn’t hops be utilized in this way more often? H. humulus Aureus, golden hops, is an ornamental form with chartreuse foliage. In any case, a hops bine is a big, strong-growing plant: contain via pruning.
PHA plants people
The September 2021 edition of The Plant Review publication of the Royal
Horticultural Society, contains a look at Chicago’s Morton Arboretum, written by Vineyarder Matt Lobdell, its curator of Living Collections. Matt Lobdell has developed a career in plant sciences and curatorial practice, after having been a summer intern at Polly Hill Arboretum, and continues his relationship with PHA as a research associate. (See bit.ly/3m9WeFK)
Matt was the first nine-month curatorial intern in 2008 at the Polly Hill Arboretum. Since that time the arboretum has launched several public garden careers in plant curation and plant records. Former 2013 intern Emily Ellingson has recently been hired as the next curator-assistant director at PHA and begins work Nov. 1.
“We’re pleased to have Emily join our team and proud that so many of our interns are thriving and making a difference in Public Gardens. My hope someday is that we can get permanent funding for the curatorial internship through an established endowment.” (Tim Boland, PHA executive director)
In the garden
Anti desiccants: Anti-desiccants are formulated with proprietary waxes and other substances to protect and prevent plants from transpiring and losing out moisture through their foliage pores, buds, and bark.
In planting shrubs recently, I found dry soil one foot deep. Soils are dry, ponds are low: yes, even despite the general opinion that we have received lots of rain this past summer and early fall. Water supplied to the surface must moisten the uppermost layer to its capacity before passing through to the next. Light rains do not even reach the lower levels, and run-off cancels out heavy rainfall.
This may translate into sudden withering or leaf drop if adequate supplemental watering is not provided. Going into winter, newly planted trees and shrubs benefit from protective mulching and spraying with anti-desiccants.
Label dahlias before frost. Burn berried bittersweet and multiflora rose used in arrangements, to prevent spread of these invasives.