The showy white bracts of the kousa dogwood blossom surround a greenish cluster of tiny flowers.
The kousa dogwood is similar to the flowering dogwood (Cornus florida): Both have small, inconspicuous flowers surrounded by large, showy bracts. The flowers of the kousa dogwood are greenish and arranged in little clusters just a half inch (1.5 cm) across. But the four bracts surrounding each flower cluster are each 1-3 in (2.5-7.5 cm) long, and very flashy. They typically start out white, then age to pink or rosy red. The late spring flower show is followed by fleshy red fruits about an inch (2 cm) in diameter that look a lot like raspberries. The various cultivars of kousa dogwood range from 10-30 ft (3-9 m) in height at maturity, and most have a similar spread. The leaves are about 3 in (7.5 cm) long and they usually turn a beautiful shade of purple-red in autumn before dropping. There are numerous named selections in the trade. Michael Dirr in his classic, Manual of Woody Landscape Plants, lists no fewer than 88 cultivars of this popular ornamental! 'Satomi' has abundant rosy pink flower bracts in spring and dark purple foliage in autumn. 'Gold Star' is smaller and bushy, to 8 ft (2.4 m) tall. 'Snow Boy' has white margins on the leaves. Cornuskousa var. chinensis 'Elizabeth Lustgarten' has a weeping habit. In addition to the many named selections, there are available several hybrids from crosses with other Cornus species, noteworthy among these are those in the patented Steller Series®.
Sunbeams light up a branchful of 'Milky Way' kousa dogwood blossoms. Click to download a large version.
Location Cornus kousa is native to Japan, Korea and China. It has been cultivated, bred, cross-bred and selected in Western gardens since at least 1875.
Light: Grow kousa dogwood in full sun to partial shade, but expect the best flowering in full sun. Moisture: Established specimens are relatively drought resistant. Hardiness: USDA Zones 5-8. Kousa dogwood is more cold hardy than Flowering dogwood (C. florida), but doesn't do as well in hot, humid climates. Propagation: The seeds germinate readily, but, of course, may not produce plants that look like the parent. In fact, the seedlings are said to be quite variable. Young, fast growing softwood cuttings taken in spring can be rooted in potting mix, with the best results obtained under mist or in an enclosure.
Unlike the American native flowering dogwood, Cornus florida, the kousa dogwoods smother themselves in blossoms in late spring and early summer after the foliage has appeared.
The kousa dogwood makes a fine specimen tree or shrub in a small yard. Young specimens are upright and conical, but they develop horizontal branches and become more wide spreading as they age. The plant is beautiful in all seasons with its spring display of white-aging-to-pink bracts and its vibrant purple foliage in autumn. Kousa dogwood is easy to grow in most any neutral to acidic soil. The raspberry-like drupes are edible, but not particularly delicious, although some of the named cultivars are grown for their fruit.
The kousa dogwood is one of the American Horticultural Society's "75 Great Plants for American Gardens." Especially noteworthy is the fact that kousa dogwood is resistant to dogwood anthracnose, a fungus disease that has decimated many populations of the American species, flowering dogwood (Cornus florida).