Plant Care
Dogwood Diseases
| Jun 28, 2022
There are two fungal diseases that affect Dogwood trees in the Philadelphia region: Powdery Mildew and Anthracnose. While doing estimates over the weekend, Alex and I have noticed numerous Dogwoods, from Haverford out to Paoli, that have one of these diseases. If your Dogwoods do not have vibrant, healthy green foliage, or aren’t blooming as well as they should be, please reach out to us!
Powdery Mildew: Powdery Mildew is a fungus that has become much more widespread in our region in recent years, favoring our warm and humid environment. Powdery Mildew tends to attack that year’s new shoots and leaves trees and shrubs, which stunts their overall growth, diminishes bloom size, and weakens the tree or shrub. Powdery Mildew steals moisture from the tree which can lead to water-stress.
Primary host trees: Crepe Myrtle, Dogwood, Fruit Trees (such as Apple and Cherry)
What to look out for: White, talcum powder-like growth on the top of the plant’s leaves, especially new growth. The fungus usually spreads first on the lowest branches because those receive the least amount of sunlight. If left untreated, the fungus can spread to all foliage.
Powdery Mildew on Dogwood.
Anthracnose: Anthracnose is a fungus that also affects numerous species of trees in our region. Anthracnose is a persistent fungal infection that requires annual treatment because it over-winters in the tissue of the tree’s twigs. In the Spring, the fungal spores are transported to the tree's new shoots and leaves.
Primary host trees: Sycamore, White Oak, Dogwood
What to look out for: Brown spots on the leaves or flowers of the Dogwood tree. Brown, sometimes curled, edges of the leaves. Early leaf drop and complete defoliation in sever cases.
Dogwood Anthracnose.
Luckily, both Powdery Mildew and Anthracnose are treatable fungal diseases that do not usually cause the tree to die. Remember, the best plant health care program is a preventative plant health care program. Even if you do not notice that your Dogwood are exhibiting signs and symptoms of either of these fungal diseases, annual fertilizing will help them remain strong and resistance to these diseases down the road. Fungicide treatments are available both as foliar-applied sprays and soil- or trunk-injected formulas. A simultaneous deep root feed will give the tree or shrub an additional nutrient boost to help fight off the disease.