By Dina Lehmann-Kim, Extension Master Gardener
The Shade Garden at Bon Air Park in Arlington is one of the smallest of the demonstration gardens maintained by the Master Gardeners of Northern Virginia. Located off Wilson Boulevard at 850 N. Lexington St., the garden hosts nearly 100 different plant varieties, a few of which may be unfamiliar, if not unusual, to visitors.
Among its collection is Tradescantia virginiana (spiderwort), a native plant that can grow 2 feet high with a mass of long, spear-shaped leaves. Beginning in April, long round stems with large clusters of buds begin to appear. Each bud holds a flower that blooms for only one day, with subsequent flowers emerging from the other buds. Flowering can last six to eight weeks. If the plant is cut back after flowering, it may rebloom in the fall. Flowers can come in many colors, ranging from bright white to purple, blue, and even red. Visitors to the Shade Garden can enjoy the white, lavender, and purple varieties.
This plant does well in shade, but thrives in full sun. It is slow to spread and does not suffer from serious insect problems or diseases. It can be used as a border plant, an accent, or in a mass planting. In the Shade Garden it is used as an accent plant in zones 1, 2, and 5.
Another unusual plant found in the Shade Garden is Nectaroscordum siculum (honey garlic). This spring bulb is located at the base of the garden’s redbud tree. It belongs to the Allium family – the same family to which culinary garlic and onion belong. If one were to crush its leaves, a scent redolent of garlic would emerge. Its red and white hexagonal flowers dangle like little bells from arching stems that form a circle around the main stem which can reach 4 feet high. It makes for an unexpected accent plant.
A third plant of interest from both a botanical and etymological perspective is Yucca filamentosa (Adam’s needle). Native to the southeastern United States, it is commonly seen in the northern Virginia metro area. Reminiscent in appearance to what some might think of as a desert cactus, it has thick, sword-shaped leaves with hairy edges. Like desert plants, Y. filamentosa can tolerate dry conditions and full sun, though it seems quite happy in its shady location in zone 5 of the garden.
In addition to its cactus-like appearance, this plant has another unusual quality – a unique relationship with an insect – the Yucca moth. In fact, each is indispensable to the other for survival. This relationship is called “mutualism” and refers to the fact that each organism benefits from the other without experiencing harm. The moth’s larvae depend on Yucca seeds for sustenance, and the plant itself can only be pollinated by the Yucca moth. In late spring, the Yucca sends up a 5- to 6-foot stalk which hosts a mass of white, waxy, bell-shaped flowers.
Gardeners in the northern Virginia metro area may wish to add any of these plants to their collection as accent plants for both interest and unusual beauty.
Tradescantia virginiana (spiderwort)
Rosenkranz, G. “Tradescantia virginiana (spiderwort).” University of Maryland Extension. https://extension.umd.edu/ipm/landscape-management-nursery-production/tradescantia-virginiana-spiderwort
“Tradescantia virginiana, Spiderwort.” Tried and True Native Plant Selections for the Mid-Atlantic. Master Gardeners of Northern Virginia.
Nectaroscordum siculum (honey garlic)
“Unusual Spring Flowering Bulbs.” Nebraska Extension: Hort Update. https://unlcms.unl.edu/ianr/extension/hort-update/BulbsUnusual
Yucca filamentosa (Adam’s needle)
Moisset, B. “Yucca Moths (Tegeticula sp.).” United States Department of Agriculture, Forest Service. https://www.fs.fed.us/wildflowers/pollinators/pollinator-of-the-month/yucca_moths.shtml
Ramsay, M. and J. R. Schrock. 1995. “The Yucca Plant and the Yucca Moth.” The Kansas School Naturalist 41:2. https://www.emporia.edu/ksn/v41n2-june1995/
“Yucca filamentosa.” North Carolina State University Extension. https://plants.ces.ncsu.edu/plants/all/yucca-filamentosa/