Q: Last year I had problems with my dogwood trees. The leaves became deformed and had purple marks. When do I spray this season?
A: It sounds like your dogwood had spot anthracnose on the leaves and flowers. The fungicide chlorothalonil (Daconil, etc) can be used to manage the disease. To prevent flower spots, start spraying when the flower buds show color. We’ve missed that date now but I recommend you spray your tree from now until early June at 14 day intervals. This will help protect new leaves. Make a calendar note to start spraying earlier next year.