Family: Lamiaceae

These hardy, herbaceous perennials, with attractive gray-white foliage, are useful as groundcover and border plants. The apple green leaves gradually turn silver, while the top leaves are velvety white. The inconspicuous mauvish red flowers can be dried, the leaves retaining their silvery tones.

Species

B. nigra, black horehound, has ovate leaves and grows to 1 m (3 ft). A nasty-smelling herb, it spreads rapidly and can be invasive.

Cultivation

Cuttings taken with a heel strike easily in the spring or the autumn.

Climate

Suitable for zone 8.