Kousa dogwood, Cornus kousa, is similar to the native flowering dogwood, Cornus florida. The biggest difference between the two is Kousa dogwood flowers after the leaves emerge in Spring.
Kousa dogwood reaches full flower a month after flowering dogwood, and has a more upright habit and pointed bracts.
The white ‘petals’ are actually bracts. Bracts are normally involved in photosynthesis, but when bracts are large and colorful they serve the purpose of attracting pollinators or seed dispersal. Cornus kousa is a splendid tree, with my only reservation being how late the tree leafs out.
Description and Culture of Cornus kousa
Dogwoods are classic understory trees, at home under a high canopy with bright filtered light. Kousa dogwood can grow in conditions ranging from deep shade to full sun. When grown in deep shade, flowering will be severely curtailed. Cornus kousa is most beautiful when grown with morning to mid-afternoon sun and afternoon shade.
Dogwoods are very beautiful in full sun as their flowers have the substance and color to shine instead of fade in harsh light.
Kousa dogwood is also known as Japanese dogwood. It is native to parts of Japan, China, and Korea.
Cornus kousa reaches 20′-30′ tall at maturity and can be grown as a single-trunk or multi-trunk tree. It is deciduous and prefers rich, moist, well-drained soil. Kousa dogwood is hardy zones 4-8.
Kousa dogwood is considered slightly more cold hardy than Cornus florida. Respected UGA professor Michael Dirr also suggests that kousa dogwood is more drought tolerant than Cornus florida (Dirr, Michael. 2009. Manual of Woody Landscape Plants. Stipes Publishing, Champaign, IL).
Fall color is beautiful. The berries mature to a beautiful red. Kousa dogwood provides excellent cover for birds and they eat the berries in fall.