One of the early signs of spring is the blooming of dogwood trees. Dogwoods grow both in the wild and cultivated in the home garden. Uncultivated, dogwood grow beneath the canopy of larger trees in a forest. In the home landscape, dogwood grow very well in partial shade or full sun. Dogwoods that grow in sun will be shorter with forking branches.
There are several types of dogwood tree that grow in the United States. Each of these dogwoods bloom at different times of the year. Most people think of the Flowering dogwood, Cornus florida, when they think of dogwoods. These trees bloom in March across the country. Other dogwoods include kousa dogwood, Cornus kousa, and the Cornelian cherry dogwood, Cornus mas. Kousa dogwood and Cornelian cherry dogwood both blossom in late winter.
Flower Blossoms Characteristics
What appear to be flowers on dogwoods are not true flowers. Instead they are bracts, or modified leaves that look like petals. The true flowers of dogwoods are clustered at the center of the bracts. Both Flowering dogwood and Cornelian cherry blossom before they produce leaves, while kousa produces flowers after it has produced leaves. The blossom colors may be white, pink or yellow. Trees grown from seed vary in the age that they reach maturity and begin to flower. Slow growers begin their blooming cycle sooner than fast growers.
Failure to Bloom
Dogwoods that are unhealthy or put under stress may fail to produce blossoms. Although dogwoods thrive in partial shade beneath trees, they will not produce blossoms if they grow in full shade. Dogwoods that must compete for resources with other trees or have crowded roots will also fail to set blossoms. Dogwood trees need well-drained, loamy soil. If the trees are planted in heavy clay soil that does not drain well, they will not produce blossoms.
Dogwood trees typically cycle between years in which they produce heavy blossoms and years in which they blossom lightly. Additionally, the plants set buds for early spring growth in mid-summer to early fall of a prior year. Dogwoods that experience unusual weather such as temperatures that are too cool or warm or weather that is too rainy may not set buds. If the trees are pruned after they set buds, the buds may be removed and the tree will not flower the next season.