Flowering dogwood trees are susceptible to a large number of diseases, and some of them, such as dogwood anthracnose, affect pink flowering varieties more than those with white flowers. While some of these diseases only cause minor blemishes or superficial damage, others are much more severe and may kill the tree.
Dogwood anthracnose, which occurs commonly in the eastern United States, is one of the more damaging diseases for pink dogwood trees. The disease, which is caused by a fungal infection, starts by causing small purple or tan spots on the tree's leaves. If left untreated, it can soon spread to the branches and trunk of the tree, causing large growths or cankers. These cankers can eventually grow around the entire branch or trunk, starving the trees of nutrients and causing them to die.
Crown canker is the worst disease that affects dogwood trees in the eastern United States, according to the Missouri Botanical Garden. This disease is also caused by a fungal infection and can lead to the girdling of the tree. However, this disease is more likely to kill the tree than dogwood anthracnose because it almost always occurs on the trunk of the tree, whereas anthracnose often occurs on stems or minor branches.
Gray mold, powdery mildew and Armillaria root rot are other common conditions in dogwood trees that are all caused by different types of fungus.