Enkianthus campanulatus 'Rubrum' (Redvein Enkianthus)

Redvein enkianthus, Enkianthus campanulatus, is a refined deciduous shrub from the cool mountain woodlands of Japan, and the selection 'Rubrum' is the deepest-colored of the clan. In late spring the branches hang with dozens of small, waxy, bell-shaped flowers, but where the plain species opens in cream veined with pink, 'Rubrum' pours out flowers of rich, deep red, nodding in tidy clusters at the tips of each whorl of branches. Close up the bells look almost enameled; from a distance they veil the shrub in a soft red haze.

A member of the heath family and a cousin to azaleas, blueberries, and pieris, enkianthus shares their taste for cool, moist, acidic soil and their gift for autumn color. When the growing season ends, the neat, blue-green foliage turns through a long, smoky range of scarlet, orange, and wine-red, often holding for weeks and rivaling any burning bush. Few shrubs offer two such distinct seasons of interest, red in spring and red again in fall, on so tidy a frame.

The habit is as valuable as the color. Enkianthus grows slowly into an upright, tiered shrub with distinctly layered, almost horizontal branching, six to ten feet tall in time and narrower than wide, so the plant reads as elegant and architectural rather than bulky. Use 'Rubrum' as a specimen in a woodland or Japanese-style garden, in the light shade of high pines, or in a mixed acid-soil border with rhododendrons, Japanese maples, and ferns, where the fine branch structure shows to advantage even in winter bareness.

Give enkianthus the conditions that suit rhododendrons: moist but well-drained, humus-rich, acidic soil, a cool root run under mulch, and shelter from harsh, drying exposure. In the South the shrub is happiest in part shade, while cooler northern gardens can grow the plant in full sun with steady moisture. Hardy in USDA zones 5 through 8, slow, long-lived, and almost trouble-free, 'Rubrum' rewards patience with decades of quiet, two-season beauty.