The dogwood (Cornus spp.) is an easy-to-grow, dependable tree that blooms profusely in spring, covering itself in white or pink flowers, depending on the variety. Although the tree develops a naturally pleasing shape, you might want to prune it to correct problems or control its shape and size, and pruning at the best time can help ensure a good result.
The Best Time
The dogwood is a deciduous tree that drops its leaves in late fall, becoming dormant during winter. When it's leafless, you can easily see all the tree's branches, giving you a clear view of its overall shape and making late fall through winter a good time for pruning. Do not prune later in the season, once the tree has started its new growth, to keep the tree healthy. The tree is susceptible to the dogwood borer, and pruning during the growing season might provide entry points for these pests, which can burrow into the tree's branches thorough fresh cuts.
You can start shaping a newly planted dogwood by pruning during its first few years in the ground, or you can modify the shape or size of an older tree by pruning back established branches. In either case, use a pruning saw or sharp pruning shears to make slanted cuts just ahead of the branch collar -- the area at the base of the branch where it joins a larger branch or the trunk. For a young branch, cut about 1/2 inch from the main branch, or 1 or 2 inches from the trunk for a larger branch. Avoid cutting into the branch collar area, because this can allow any infection to spread into the tree. Disinfect your pruning blade before cutting by wiping it well with rubbing alcohol, and do this again between cuts.
Pruning a young dogwood helps determine its mature shape. For example, remove all but one stem from a young tree to give it a single-trunk shape, pruning away any new, low side branches until the main trunk is a few feet tall. A dogwood grows 1 or 2 feet each year until it's about 25 feet tall. You can keep the tree a bit shorter by heading upright branches back by one-third each year, but this may produce a tree that spreads wider than the usual 25 feet. Prune away any dead, injured or diseased branches to help preserve the tree's health, and remove any shoots that appear below the tree's graft point -- a visible scar on the lower part of the trunk.
Several types of dogwoods brighten the home landscape with their showy flowers. The most common type, the white dogwood (Cornus florida), is a North American native that thrives in full sun to partial shade and has bright white flowers in April and May. The pink dogwood (Cornus florida f. rubra) also blooms in spring, but has pink or reddish-pink flowers with greenish-yellow centers. Both of these types grow in U.S. Department of Agriculture plant hardiness zones 5 through 9. The Korean or kousa dogwood (Cornus kousa) blooms later in the season, usually in May through June. Unlike the other types, leaves precede its white flowers, which have pointed petals and stand out against the deep green leaves. It grows in USDA zones 5 through 8.