Summer-blooming shrubs for shade - includes list of nurseries

Flower & Garden Magazine, June-July, 1994 by Patricia A. Taylor

Flowering Shrubs Have long been staples of shade gardens. Too often, however, people think in terms of colorful spring displays. Beautiful summer-flowering shrubs for shady landscapes are almost a garden secret.

I'd like to change the situation by sharing some of my favorite shrubs of summer. A few shrubs on my list are usually recommended for sunny sites, but all do quite well in shade, some even in full shade. They are all sturdy, widely adaptable plants that resist both diseases and pests. If you have a shade garden, you may wish to add one or more to enhance the beauty of your summer setting.

Glossy abelia (Abelia x grandiflora) bears a profusion of pink-tinged white flowers. First grown in an Italian nursery sometime before 1880, it languished in relative obscurity until receiving an Award of Garden Merit from England's Royal Horticultural Society in 1962. That honor brought its long flowering period (summer through light frosts in my New Jersey garden), shiny reddish-green foliage and ease of care to the attention of many. Glossy abelia does best in light shade and well-drained, acid soil in Zones 6 to 9; in Zone 5 some winter damage may occur.

Butterfly bush (Buddleia davidii) is generally recommended for full sun. However, it grows and blooms well in open shade, as long as it gets about four hours of direct sunlight. Left unpruned in a warm climate, butterfly bush can grow as tall as 20 feet. It blooms away until knocked out by frost; the more its white, lavender or dark purple flowers are cut, the more flowers it produces. Butterflies - as the popular name indicates - love this plant, which is suitable for Zones 6 to 9.

Lavender beautyberry (Callicarpa dichotoma) flourishes in Zones 6 to 9 when placed in a setting that receives four to five hours of sun and bright, open shade the remainder of the day. So situated, it will produce pink flowers on low, arching branches through most of July and August. The real bonus comes in September, when clusters of deep lilac fruit form; the fruits look especially lovely in fall when all the leaves have fallen. Since beautyberry flowers and fruits on new wood, it can be pruned close to the ground in March or April, thus keeping its height at a compact 3 to 5 feet.

Sweet pepperbush (Clethra alnifolia) is an Eastern native shrub valued for its ease of maintenance and fragrant white or pink flowers, which bloom in the middle of summer. Easily grown in Zones 3 to 9, it is excellent for heavy shade and wet areas. This plant is so adaptable that it can look beautiful as an 8-foot-tall informal shrub in seashore landscapes or as a clipped hedge in structured city gardens. In the fall, the foliage turns from deep green to a lovely yellow-orange.

Unlike most rose-of-sharons, which self-sow abundantly, the variety |Diana' (Hibiscus syriacus |Diana') is sterile, the result of years of breeding by the U.S. National Arboretum's Dr. Donald R. Egolf. It is a beautiful, long-blooming shrub, covered with large, lustrous white flowers that stay open so long they often gleam in the moonlight. This adaptable plant can thrive along parking lots, in city gardens and in formal borders in Zones 5 to 8. Give it four to five hours of sun, with bright shade the rest of the day. Left unpruned, it will grow 8 feet tall; pruned it can form a neat 4-foot bushy hedge.

Wild hydrangea (Hydrangea arborescens), also called smooth hydrangea, is a 3- to 6-foot shrub that bears cool white flowers during the height of summer heat. Recommended by the National Arboretum as a great seashore plant, it is also a perfect, easy-care addition to inland gardens in Zones 4 to 9. Most catalogs and garden centers offer the cultivar |Annabelle.' It reaches about 4 feet in height and has large (12 inches) rounded flower heads throughout summer.

Bigleaf hydrangea (Hydrangea macrophylla) is an old-fashioned plant that is available with two flower forms: lacecaps, showing a flat-topped cluster of small, fertile flowers surrounded by a ring of conspicuous sterile flowers; and hortensias. The familiar form with flowers clustered into large, showy globes. Both will bloom throughout summers in Zones 6 to 9 with as little as three hours of direct sun, but slightly more sunlight is even better. The color of the flowers is determined by the acidity of the soil; blue flowers result from very acid soils and pink flowers from slightly acid or neutral soils.

|Blue Billow' hydrangea (H. macrophylla serrata |Blue Billow') was discovered by Dr. Richard W. Lighty during a Korean plant exploration trip. It has intense blue lacecap flowers that add drama to summer gardens in Zones 6 to 9. Since the flowers bloom on year-old wood, it is best to prune shoots to the ground immediately after flowering. This pruning keeps the plant a tidy 3- to 4- foot rounded mound.

Oakleaf hydrangea (Hydrangea quercifolia) is such a beautiful, adaptable plant that it should be found in gardens throughout Zones 5 to 9. A southeastern U.S. native, it needs good soil, neither too wet nor bone dry, in full sun to full shade. At maturity, it will reach 5 to 6 feet with an equal spread. It is prized for both its flowers and its foliage, which turns a lovely fall color - crimson or wine red, depending on the location. The cultivar |Snow Queen' is drenched in upright cones of gorgeous white flowers in June and July. In addition to being showier than those of the species, the flowers of |Snow Queen' are less likely to be shattered by summer thunderstorms.