Back then, and yet today, Lespedeza is known first and foremost as an agricultural crop, raised for forage and erosion control. As a member of the legume family (formerly Leguminosae, now divided between Papilionaceae and two other sub-families), it also fixates nitrogen in the soil, raising the soil's fertility. Other nitrogen-fixing legumes include alfalfa, clover, peas, beans, lentils, lupines, and peanuts. Although there are several native lespedezas in the U.S., agricultural lespedezas are imported non-natives.
Lespedeza cuneata (more below), Striate Lespedeza (Kummerowia striata), and Korean Lespedeza (Kummerowia stipulacea) were introduced into the United States in the early 1900s. By mid-century large acreages were planted with these varieties. However, lespedeza use dropped sharply when other, more productive legume species and new fertilizers came into widespread use. In the interim, the original agricultural lespedezas have been improved through breeding programs to the point where interest in them as forage crops is again increasing.
But that's not the whole Lespedeza story.
I'd like to introduce you to three varieties that I grow in our gardens. My first acquisition was Lespedeza thunbergii 'Gibraltar' (see photo above), also known as Pink Bush Clover (although technically not a clover and technically not pink). It has proven to be bone hardy in our zone 5a garden, coming back vigorously every spring. A well-behaved sub-shrub, it grows about three feet tall and about as wide. The cluster of branches arises at soil level in mid-spring and grows upward and outward in graceful arches. Even when not in bloom, this plant adds beauty and interest to the garden. It gradually grows to approximately two feet.
At this point, plant growth slows until late summer, when a growth spurt sends the branches upward another foot or more. Soon pendant panicles of pinkish lavender flowers appear at the tips of the branches and dangle from the leaf axils along each branch. The blossoms, as is typical of legumes, resemble the flowers of peas. The pendant clusters are reminiscent of miniature wisteria blossoms.
To my great delight I discovered that there is an advantage to this late summer/early fall growth spurt. The shorter perennials that are neighbors to one of the lespedezas in our gardens are not in bloom at this point and the area is devoid of color. The weeping branches hide them from view somewhat and fill the area with that beautiful pinkish-lavender hue.
The second Lespedeza variety in
our gardens is Lespedeza thunbergii ‘Alba'. As the varietal name implies, its blossoms are white. It blooms a bit later, grows a bit taller, and is more upright than ‘Gibraltar.' At the back of a large bed of red annual salvia, it provides pleasing shades of green as a background for the sea of red blooms. In September the blossoms add white to the mix, providing additional interest.
A more recent acquisition is Lespedeza thunbergii ‘Edo-Shibori'. Its bi-colored blooms are especially attractive. I grow this variety in a pot, because it's a bit less hardy, and I can move it around the garden as an accent plant or locate it somewhere where I can enjoy its pendant blossoms as I come and go. Like 'Gibralter' and 'Alba', Edo-Shibori's branches are very light and flexible, moving with the slightest breeze--much like many ornamental grasses. The element of motion adds a welcome dimension to the garden scene, catching the eye as it surveys the garden landscape.
If you're looking for an unusual plant that is hardy, long-lived, easy to grow, and adds color to the garden late in the growing season, why not try a Lespedeza? You'll be glad you did!