American perennial expert Allan Armitage regards species of Epimedium, commonly called barrenwort or fairy wings, as magnificent ground covers for the garden. These plants have attractive heart-shaped leaves and prosper in the dry soils under the shade of trees, a location often difficult to vegetate. The flowers, although small and dainty, are seen in early spring.
Between 30 and 40 species of Epimedium exist, all members of the barberry family, Berberidaceae. They are native anywhere from the Mediterranean eastward to the temperate climates of eastern Asia. Gardeners then hybridized plants among various species to create more attractive selections to grow in modern shady landscapes.
Barrenworts may be evergreen or deciduous, losing their foliage in the cold of winter, depending on species. Growing from rhizomes, fleshy horizontal stems below ground, they occur in woodlands and shaded rockeries in the wild. The leaves are leathery but thin and arise on thin stems directly from the rhizome.
Most leaves are shield- or heart-shaped, but some more feathery leaves exist on some species. Sometimes the new leaves emerge in a pleasant shade of bronze before becoming green and in autumn may blush to tones of red, violet and burgundy.
The flower of barrenworts are small and usually overlooked. Appearing in spring or early summer, the tiny cup-shaped flowers with spurs are masked by the foliage. The flowers range in color: yellow, cream, white, pink, red or purple.
Six species make good garden choices. The European native alpine barrenwort (Epimedium alpinum) bears dull red flowers that extend above the leaves. Longspur barrenwort (Epimedium grandiflorum) is native to Japan and has large leaves with multicolored flowers. Reddish-brown and green leaves make a nice foil to the yellow flowers of the Algerian barrenwort (Epimedium perralderianum). Fuzzy leaves arise without stems from the rhizome on the yellow-flowering Epimedium pinnatum from Iran.
Two hybrid species to consider garden-worthy include Young's barrenwort (Epimedium x youngianum) and the red barrenwort (Epimedium x rubrum).
In general, plant barrenworts in fertile, humus-rich soils that are moist but drain quickly after rains. Place them in a location where drying winds are not common in summer or winter. Shelter the plants with a partial shade exposure, receiving broken or dappled light through the shade of tree branches. Direct hot sunlight in dry soil situations browns leaves; however, these perennials tolerate the dry soils under trees perfectly.
Whether an evergreen or deciduous species, use barrenwort as a ground cover under large shade trees in a woodland or shade garden where few other ornamental plants prosper. Large masses or sweep of barrenworts make alluring displays, especially when the foliage changes color in spring or the chill of autumn. Small clumps of this perennial mix in well with other shade perennials in a flower border, too.