Epemedium grandiflorum is also called “bishop’s hat” is one of my favorite ground covers. It is one of those plants which look like maidenhair fern, that looks dainty and delicate but is really as tough as they come adaptable, easy to grow, and hardy to zone 3.
The small spurred flowers are supposed to resemble a bishop’s miter, but they look to me like miniature columbines. Epimedium grandiflorum, the large-flowered barrenwort, or bishop’s hat, is a species of flowering plant in the family Berberidaceae, native to China, Japan, and Korea.
They come in various colors depending on the variety of white, pink, red, lavender, and yellow, which appear in late spring. Rose Queen is a good red and Nivum has large, showy white flowers. The heart-shaped leaves are pinkish when they first emerge in spring. They overlap in beautiful soft-looking mounds and last even into early winter, after turning a reddish-bronze color.
Moreover, Epimedium grows slowly when first planted. But it looks like the tortoise that beat the hare slowly and steadily established large, vigorous clumps. It will grow well even around the bases of trees, where it is a graceful addition. Epimedium prefers part shade but will grow in the sun if you give it the moist, humusy soil in which it does best.
Soil should be well-drained and slightly acidic. Since it is shallow-rooted, try not to cultivate around it, but instead apply a light mulch to control weeds. Divide in spring, preferably while plants are dormant cutting the tough roots with a knife.