The ornamental dogwood tree is a popular specimen due to its vibrant flowers and bright red berries in the fall and winter.
However, you must take care in selecting and maintaining your dogwood tree as they are susceptible to a variety of diseases.
The effects of these diseases range in severity from disfiguring blemishes to the death of the tree.
If your tree becomes infected, quick identification and treatment can save its life.
The three main types of leaf/flower diseases are Powdery Mildew, Spot Anthracnose and Septoria Leafspot.
They do not usually cause permanent damage but are disfiguring.
Severe infestations will eventually weaken the tree and make it susceptible to other, more dangerous, conditions.
Powdery mildew will appear as light green to yellow spots.
Then, threadlike white patches develop and the plant gives the appearance of having been dusted with flour.
Spot anthracnose affects the flower petals, leaves and young shoots.
The symptoms are small circular reddish-purple spots appearing on the petals in early spring.
Spots on leaves are small and dark purple in color, but the centers may turn pale yellow-gray and drop out.
Septoria leafspot usually does not become severe until mid-summer.
The spots appear angular and are bordered by veins.
At first, they are a uniform, purplish color, but later in the season the centers become grayish, while keeping the dark purple border.
The centers rarely drop out.
The spots are much larger than those caused by spot anthracnose.
The primary disease affecting the wood or stem of the tree is a Dogwood Cankers.
A canker is a slowly developing blemish on the main trunk or the larger branches.
Cankers may be either: A sunken area in the bark that may ultimately circle the trunk and result in the death of the tree above the area, or a swollen area with roughened bark on the trunk or main branches.
These roughened areas are often invaded by insects.
Leaves on diseased trees may be smaller than normal and shed prematurely.
Dogwood anthracnose is the most serious disease to affect dogwood trees.
Initial symptoms are small purple-bordered leaf spots or larger tan blotches, especially on leaf margins.
These initial symptoms can be confused with the less serious Spot anthracnose.
Affected leaves do not fall in the autumn and frequently remain on the tree until spring.
The fungus can spread to the twigs and, in some cases, to the trunk, causing brown, elliptical cankers.
Sprouts may develop from the cankers, and also may become infected.
Untreated, the cankers this fungus produces will kill the tree.
Dogwood trees are a beautiful addition to your landscape, but can develop major problems without the proper care and attention.
First, select certified disease free plants from a nursery or garden center.
Do not transplant wild dogwoods as they are more likely to carry disease.
Secondly, do your research and plant your dogwood in the right kind of soil and sun.
Finally, if your tree shows signs of disease, treat it immediately and don't allow a minor problem become a life threatening infestation.