As a professional gardener, I’m always on the lookout for underutilized plants to break the ho-hum factor in landscapes. I especially covet ones that flower. Tell me about an underutilized, flowering and low-maintenance specimen: even better. Toss in a high level of deer resistance, and I’ve hit the jackpot. I’ve found Lespedeza thunbergii.
That Lespedeza thunbergii – a.k.a. Thunberg bush-clover – belongs to the family Fabaceae is immediately evident. Smooth, blue-green, trifoliate leaves clothe supple branches that arch gracefully earthward. Six-inch-long racemes of pendant pink, rosy purple or white pea-like blooms appear on the upper portions of shoots, combining to form panicles up to 30 inches in length. Here in southeastern North Carolina, flowering begins in late April or early May. After taking a break during the sultriest weeks of high summer – as does anything with any sense – bloom recommences, peaking in September and continuing well into November.
It’s a mystery to me why such a lovely, easy-care plant isn’t more common in the trade hereabouts. Introduced to Western gardens from China and Japan in 1837, this herbaceous subshrub dies back to the ground after hard frost, even in Zone 8b. Prune the stems down to 6 inches in late winter, then stand back: bush-clover can reach a height of over 6 feet and an equal or greater spread in a single season.
In the four years since I started using L. thunbergii in client gardens, I have observed no disease problems despite summertime round-the-clock oppressive heat and humidity levels, nor any pest damage, not even a sample nibble from the deer herds that plague our area. Thriving in full-sun locations, its form is just as lovely in up to half-day shade, but flowering diminishes. Although it shines brightest in moist, rich soils, it performs nearly as well on hot, dry sites. Propagation couldn’t be simpler: Whack a couple suckers off the main plant and pot them up. Transplanted seedlings take readily to life in containers as well.
Name: Lespedeza thunbergii cvv.
Common name: Thunberg
Hardiness: Zones 5/6 to 11
Mature height: 5 to 6 feet
Mature spread: Up to 10 feet
Classification: Herbaceous subshrub
Landscape Use: Specimen, perennial gardens, mixed shrubberies
Ornamental Characteristics: Smooth, trifoliate blue-green foliage; 6-inch-long racemes of pink, rose-purple or white flowers form panicles up to 30 inches long; graceful, arching habit; ease of maintenance; highly resistant to deer browse
Lespedeza appears to have no pH preference. It grows equally well for me in the basic sand of coastal North Carolina as in the heavy, acid soils of north Georgia. (In the fifth edition of his Manual of Woody Landscape Plants, Dr. Dirr describes Thunberg bush-clover as “… really the beauty … of the genus.”)
Two cultivars occasionally come available in the local trade: ‘Pink Cascade’, with pink flowers and a slightly more compact habit than the species; and ‘Gibraltar’, with deep, rose-hued blooms that Dr. Dirr finds difficult to distinguish from the species. Allegedly, ‘Alba’, a more upright, white-flowering version, and ‘Variegata’, with white-streaked foliage and rose-purple blooms, exist out there somewhere.
In the landscape, Lespedeza thunbergii works as a specimen, in perennial gardens or as part of a shrubbery. I’ve alternated it with pruned Loropetalum chinense var. rubrum ‘Ruby’ to screen a garage, and dotted it along the perimeter of a large corner lot to unify an otherwise eclectic mixed planting. It’s got a beautiful shape, clean blue-green foliage, a long bloom period, it’s low-maintenance and Bambi doesn’t like it. Who could ask for anything more?