Dogwood Looks Poorly Again This Growing Season
My dogwood, a spreading variety that deer prune, looks worse than I've ever seen it before. It is a variety from Spring Grove Cemetery in Cincinnati. I purchased it from Wayside Gardens about 20 years ago. Late last summer, or even last fall, I notice dead branches and loss of leaves. Since then I've pruned perhaps 6 dead branches. I researched online, decided it was some kind of blight that needed some kind of horticultural oil and...did nothing. What should I do now? I want to save my dogwood. The file named DogwoodBlight.jpg holds an image I took 06Jul18. The tree looks even worse today.
We cannot see the leaves closely enough to be able to diagnose the problem. You are welcome to send more photos, both clear close-ups and the entire tree.
Dogwoods are forest understory trees. They like partial shade and organic soil. If this is not the conditions it is in, it may be weakened by that, which makes it susceptible to diseases.
You may need to replace it: http://extension.umd.edu/learn/how-do-you-decide-when-remove-tree
The tree in question gets partial shade. It is sheltered from wind. I wouldn't call the soil "organic".
Here are more pictures
We viewed the photos that you sent. The photos did not show the whole tree and around the base. In general the tree looks thin, weak and is declining. There is not much you can do to revive the tree. It will limp along and you will have to eventually replace it. All you can do is prune dead wood, keep the tree well watered during dry periods, and make sure mulch is no thicker than several inches.
Some reasons for decline include planting too deeply, poor soils, excessive mulch, poor drainage, etc. If there was injury to the trunk or some stress the tree may be susceptible to the dogwood borers or cankers. Dogwoods can also be susceptible to fungal diseased like spot anthracnose and powdery mildew.
See our publication for more information. You may want to plant another species of tree based on the site conditions and the mature height and width of the tree.
If you decide to plant another dogwood, take a look at the planting process and select disease resistant varieties.
also, see When to Remove A Tree