Crack in dogwood trunk
Hello. I would like some advice on how to treat my dogwood tree (about 7 years old), which has a crack in the bark along the southwest side (which I've read may be attributed to sunscald). I've attached a picture so you can see the extent of the damage. Insects are actively crawling into it, and last spring the leaves were very wilted. This spring it seemed relatively healthy, but I'm sure it won't make it too much longer without treatment. It is in partial sun in a townhouse neighborhood. Thank you!
We viewed your photo. It looks like the dogwood may be planted too deeply and there is excessive mulch around the trunk. All you can do is pull back the mulch and carefully remove the soil from the circumference of the trunk to the point where the trunk flares out into root growth. Make sure mulch is no thicker than several inches and away from the base of the trunk. See our publication on Planting Too Deeply. http://extension.umd.edu/sites/default/files/_images/programs/hgic/Publications/HG86%20Common%20Abio...
It looks like the wound is trying to heal itself. We do not recommend a pruning paint or insecticide. If it can, the trunk will do this on its own.
Keep the tree well watered during dry periods. There is nothing else you can do.