Dogwoods include a quite large group of pretty diverse flowering woody trees and shrubs within the genus Cornus. So what’s the difference between Cornus florida and Cornus kousa?
Here is the short version; Cornus florida is the old standby, being the most commonly recognized and usually the most readily available of the dogwood trees to be found at local garden centers. This tree thrives in almost all areas of the PNW, and is known for its showy white, or sometimes pink or red, springtime blossoms. The tree does well in full sun or partial shade, and will actually adjust its shape and form to adapt to whatever conditions of light it finds itself growing in.
A flowering dogwood grown in full sun tends to develop a more upright shape, holding its branches closer to the main stem; one grown under shady conditions will assume more of a spreading habit allowing its branches and leaves to develop out over a wider area to capture more light for photosynthesis. The smooth, dark-brown bark of the young dogwood tree will break up into small scaly blocks as the tree grows and matures. Most dogwoods are rather slow growing and are a welcome addition to the home landscape right from the start, with colorful spring blooms and dark-green oval leaves that turn to a showy crimson red in the autumn.
Cornus kousa has gained more popularity over recent years, particularly because of its resistance to dogwood anthracnose. The kousa dogwood tends to have leaves that are a bit smaller than the leaves of the florida; also, the blossoms appear a little bit later in the spring and are somewhat smaller, with the white petals having a slightly greenish appearance. The kousa dogwood is somewhat more drought tolerant than the florida.
All dogwoods are rather shallow rooted and will suffer if periods of hot dry weather prevail. Keep a close eye on your dogwood trees during dry spells. If the leaves start to turn a paler shade of green or start to curl on the tips, bring out the water hose and be very generous and frequent with your irrigation.
Check out the many varieties of dogwoods we just got in!