Summer Flowering Shrubs
Only rarely does the home gardener of today indulge a collector’s instinct in the matter of trees and shrubs. Not only is his span of years somewhat short, but also his areas for gardening seem to have shrunk. However, the Summer-flowering shrubs have a special significance for the decoration of Summer resorts and vacation cabins, as well as helping the year-round garden through difficult months. Well-established shrubs are less affected by Summer drought, for example, than are annual or perennial plantings. Hence it may be useful to point out a few shrubs whose flower display in Summer entitles them to a second consideration, granting the while that they might not equal in points other candidates for space in the garden. All are generally available from nurseries.
Hydrangea Aristocrats
One Plant Buyers Guide flatly states “all nurseries” as a source for peegee hydrangea, but this popular plant need not be used in all gardens. The discerning garden picture-planner has, in fact, banished it. None of the reasons for its disfavor apply to the oakleaf hydrangea, Hydrangea quereifolia. Instead we have a low mound, usually not over three feet (it grows to six feet in warmer climates), of foliage of an interesting oak-leaf pattern topped from the middle of July to the end of August with flat clusters of tiny, perfect flowers with a scattered fringe of wide-petalled sterile flowers, white turning purplish. Another excellent plant for covering a rock or stump in part shade is the climbing hydrangea, Hydrangea petiolaris, which supplies white corymbs in early Summer.
Unusual Legumes
The pink indigo, Indigofera aniblyantha, has continuous Summer bloom. It has been recorded in Rochester as early as June fourth, but July and August see it well in flower. Not showy, but charming, are its bright pink, tiny, pea flowers borne many to a stem; it has small leaves in the locust pattern. In our area it is Winter-hardy, which permits pruning hack to a central trunk and Summer heights of new wood to four feet or so. E. H. Wilson who brought it out of China in the year 1908 called it a pleasing shrub.
Almost too late for this Summer collection in our climate, thunberg lespedeza, Lespedeza thunbergi, is usually in flower by early September. Its dark, reddish-purple flowers, pea-shaped and a balf-inch long, are abundant, terminating four to five foot stems clothed with three-parted leaves whose upper dark and lower light green surfaces contrast pleasantly. The stems die to the ground, and new growth in the Spring starts rather late. It should he associated in a garden scheme with some early maturing perennials.
Attractive Chestnuts
The most splendid mass flowering effect in Summer will surely that of bottle-brush buckeye, Aesculus parviflora, and wherever there is room for its development into a 15-foot shrub and to sucker out into a broad, many-stemmed group, its late July flowering will be most rewarding. If one encourages sucker shoots, it will produce a mound of foliage of a neat horse-chestnut shape clear to the ground, with nearly every shoot terminating in foot long spikes of white flowers, with their several pinkish stems extending beyond the petals to give the brushy effect. This shrub, though from South Carolina southwards, is perfectly hardy, as is Aesculus parviflora serotina from Alabama, highly prized in Rochester for its longer, plumy flower spikes which come three weeks later (about August 10th).
Shrubs of Distinction
As a specimen plant for July flowers Japanese stewartia, Stewartia pseudocamellia, is unexcelled. At any time it is a distinctive plant; its habit is that of a small tree, with one main trunk and branches turning upwards surrounding it to make a pyramidal shape; its bark is reddish and flaking. The neat leaves have the good substance typical of the tea family and show purplish coloring in the Autumn. The flowers are white-cupped, with a bunch of orange-tipped stamens in the center for contrast, about two and one-half inches across with the petals united at the base. Flowers that fall from the tree carpet the ground beneath. Flowering is continuous for three weeks.
The five-stamen tamarisk, Tamarix pentandra, is one which flowers on the current season’s growth of wood, hence it is not until late Summer that its light pink fluffy plumes expand on the stems covered with minute foliage. Tamarisk is an ideal shrub for the seashore, since it tolerates sea spray. It will make a tall plant of 12 feet or so, or it may be kept pruned back to more compact form. I have not grown the new Summer Glow tamarisk, but presumably it is derived from the above species either as a brighter-colored clone or a hybrid.
To our August-flowering native summer-sweets, the Japanese clethra, Clethra barbinervis, adds its small tree stature with ornamental flaking bark and numerous clusters of white flowers in drooping cluster-spikes which have a delicate spicy fragrance. Reddish tints are prominent in the young leaves and in the stems in the Spring; its Fall coloring is rich.
August Color
Onwards from the middle of August there is good flowering with the chaste-trees; actually not tree-like at all, they are best treated as annual shrubby growths from the ground. Both species of vitex are good; my preference is for
To have earned the name of harlequin glory-bower a shrub must have distinctive points of interest. This common name for Clerodendron trichotomum indicates the variations of coloring through its flowering and fruiting which begin in early August and extend until frost. At other seasons its sumac-like habit, its coarse leaves, catalpa-shaped, with an unpleasant odor, its tenderness above ground to extreme cold and its tendency to roam underground do not recommend it. But, when its long-tubed white flowers, with spidery stamens, fill the air with a fine perfume on an August morning, the scales dip in its favor. Surrounding the base of the flower is a pinkish calyx which, as the bright blue berried fruit forms, opens wide, and deepens to a crimson color. Finally, the fruit turns blue-black.
Late in August and early in September a neat little shrub about two and one-half feet high, with small aromatic leaves, is covered with spikes of dark lavender. It is mint-shrub, Elsholtzia stauntoni, a half-shrubby plant from northern China. It winters fairly well when protected by a snow cover, but a severe Spring pruning is usually in order. If its late Summer show pleases you, gather the seed in October, and from a Spring sowing you may not only increase your plantings, but also have a flower display the first year.
Adaptable to Shade
Shade is most appreciated in Summer gardens when the play of light and shadow softens the glare of full sun. With due precaution to avoiding overpowering competition from the roots of elm or maple greedy for all the food and moisture, the Summer-flowering shrubs will tolerate shaded areas in the following rough approximations. For full sun to light shade use indigofera, lespedeza and elsholtzia in mass planting and tamarix and stewartia in groups of three or as specimens. In light to half-shade vitex for medium, aesculus for large mass planting and clethra for a group or specimen. At some sacrifice of bloom, clerodendron and hydrangea may be used where there is sunlight for less than half the day.
by B Harken
Comments
Feel free to leave a comment...