Native to the Eastern United States, dogwood trees (Cornus florida) are among the most beautiful of flowering, ornamental trees. The dogwood tree offer clusters of bright blooms in spring, followed by glossy green leaves during the summer and brilliant fall foliage. Their branches have an open form and pleasing appearance and their bark has an interesting texture for winter interest.
Dogwoods, which grow in U.S. Department of Agriculture plant hardiness zones 5 through 9, have a reputation for being difficult to establish. For success, you must duplicate their natural growing environment. Native dogwoods are typically found as understory trees, growing under tall pines or deciduous trees. In this environment, they experience partial shade and protection from the wind and cold. They live in a highly organic, slightly acidic soil that is amended annually with pine needles, leaves and other organic matter.
Planting Dogwood Trees
In the home landscape, plant dogwoods in partial shade. Plant them where they are sheltered from the wind by a wall, building or larger trees. When possible, amend the soil in an entire bed before planting with compost, mini bark mulch or pine needles. Dogwoods don’t tolerate damp feet, so it’s important to make sure the soil drains well. Dogwoods prefer soil with an acidity level between 5.2 and 6.0. Add sulfur to alkaline soil the year before you plant the tree.
Plant dogwoods in spring. Dig the planting hole as deep and twice as wide as the tree’s rootball. Don’t dig up dogwoods from the wild because they’re often misshapen and won’t grow or bloom well. Use nursery transplants, which may either be grafted rootstocks or seedlings. Place the dogwood so it sits at the same soil level as it sat in the nursery. Mulch a young dogwood with 3 to 4 inches of bark or wood chip mulch and water frequently as the tree becomes established. A mulch helps keep the soil moist, cuts down on weeds and also prevents injury from weed trimmers.
Don’t fertilize the tree immediately after planting. Instead, fertilize it lightly the following spring with ¼ cup 10-10-10 fertilizer. Thereafter, fertilize mature trees with no more than ½ cup 10-10-10 fertilizer. If the tree sits in a fertilized lawn, it probably won’t need additional fertilizing.
One of the most unique aspects of dogwoods is their habit of horizontal branch growth. These open branches don’t require a lot of pruning to maintain their shape. Too much pruning can disfigure them. Prune in winter to remove branches that are dead, diseased or rubbing against each other. You can remove a few of the lower branches, if necessary.
Dogwood Tree Pests and Diseases
Dogwoods are subject to more diseases and pest problems than most trees. Some of them, such as anthracnose leaf spot, powdery mildew and botrytis leaf mold, cause only cosmetic damage. Dogwood anthracnose canker is usually fatal to the tree. It causes the leaves, branches and tips to curl, turn brown and die back. The tree slowly loses vigor and dies within three to five years. Armillaria root rot and crown canker are two other potentially fatal diseases of dogwood trees.
To prevent problems, plant disease-resistant trees adapted to your area. Make sure the soil drains well and avoid injuring the tree during planting. Use soaker hoses, rather than overhead sprinklers, which can spread disease. Finally, in some cases, infected trees can be treated with fungicides. Call in a professional to properly identify the condition and recommend a treatment.
Dogwood borers and applewood borers are two potentially lethal insect pests. These moth larvae bore into the cambium layer of the tree, eventually killing it. You may notice small, wet areas on the bark or a frothy, white film. Once the tree becomes infected, there is little you can do.
To deal with these pests, spray the limbs and trunk well with a permethrin pesticide in early spring, when the moths are active. If you notice boring activity, insert a long wire into the hole to kill any borers nearby. Do general pruning tasks in the winter when moths aren’t active, but promptly remove any branches infested with borers and burn them.
Want to learn more about growing dogwood trees?
Growing Wisdom goes over the basics of the dogwood tree on YouTube.