Crown Canker on Dogwood: Causes, Symptoms, and Management

Dogwoods are among the most beautiful and popular ornamental trees in North America. They are known for their showy flowers, vibrant foliage, and attractive bark. However, these trees are susceptible to various diseases that can affect their health and appearance. One of the most common and destructive diseases is crown canker. In this article, we will explore the causes, symptoms, and management of crown canker on dogwood trees.

What is Crown Canker?

Crown canker is a fungal disease that affects the bark and cambium layer of dogwood trees. It is caused by the pathogen Cryptodiaporthe canker, which enters the tree through wounds or natural openings in the bark. Once inside, the fungus spreads rapidly and causes extensive damage to the tree's vascular system. As a result, the tree may experience dieback, stunted growth, and eventually death.

Symptoms of Crown Canker

The symptoms of crown canker on dogwood trees can vary depending on the severity of the infection. In the early stages, the tree may exhibit small sunken lesions or cankers on the trunk or branches. These cankers may ooze sap or produce a foul odor. Over time, the cankers may enlarge and merge, causing the bark to crack and peel away. This exposes the underlying wood, which may be discolored and decayed.

As the disease progresses, the tree may start to show signs of stress, such as yellowing or wilting leaves, reduced growth, and sparse foliage. The tree may also develop dead or dying branches, which can become brittle and pose a safety hazard. In severe cases, the entire tree may die within a few years of infection.

Causes of Crown Canker

Crown canker on dogwood trees is caused by a combination of environmental and biological factors. The disease is more common in trees that are stressed or weakened by drought, poor soil conditions, or other diseases. Additionally, injuries to the bark, such as pruning cuts, insect damage, or mechanical damage, can create entry points for the fungus.

The fungus that causes crown canker can survive in infected plant debris or in the soil for several years. It can also be spread from tree to tree by insects, wind, or rain.

Management of Crown Canker

Preventing crown canker on dogwood trees is the best approach to managing this disease. Here are some tips for preventing crown canker:

1. Plant dogwood trees in well-drained soil with proper sunlight and air circulation.
2. Avoid planting trees in areas where the disease has occurred previously.
3. Maintain good tree health by providing adequate water, nutrients, and pruning.
4. Minimize bark damage by avoiding unnecessary pruning or physical damage to the tree.
5. Remove and destroy infected plant material immediately to prevent the spread of the disease.
6. Avoid overhead watering, which can promote the spread of fungal spores.
7. If necessary, apply fungicides according to label instructions.

If you suspect that your dogwood tree is infected with crown canker, it is important to take action immediately. Contact a certified arborist or tree care professional for assistance in identifying and treating the disease. They can also provide advice on how to manage the disease and prevent future infections.

A dogwood tree with crown canker

Crown canker is a serious disease that can cause significant damage to dogwood trees. It is important to be aware of the symptoms of this disease and take steps to prevent its occurrence. By following proper tree care practices and seeking professional help when needed, you can help ensure the health and longevity of your dogwood trees.

fungal disease, ornamental trees, vascular system, environmental factors, soil conditions, arborist, tree care professional.