Sick Dogwood Tree
I have a sick 20-year old dogwood tree with southern sunny exposure in the city. Although it flowered beautifully, two problems have developed since it leafed. The first, which I've not experienced before, has to do with the top tier branches. Their leaves are approximately 1/13 the size of the bottom tier branches. Second, some of the leaves on the latter have brown spots which eventually take over the leaves and make them wither. This has happened over the course of several summers. What's wrong and how should the tree be treated? Also, is there something I should be doing to a new healthy 8 foot dogwood to prevent these problems from occurring in the future?
District of Columbia County District of Columbia
This may be dogwood anthracnose, a fungal disease. Please read closely the following article from our website:http://extension.umd.edu/hgic/dogwood-anthracnose-discula-trees
Note that is also refers you to our IPM: Dogwood publication, which features more photos and a diagnostic chart of many possible causes, plus info and controls.
Looking under the leaf should be a key clue. You can also send us photos of the leaf undersides.
If your tree has been infected with anthracnose for several years, it may have caused branch dieback (upper canopy.) Follow the recommendations on our website.