my lilac bush on the east side of my house has white powdery substance on many of the branches from the ground to the foliage. What do I need to do to treat this? Thank you
Hartford County Connecticut
Sounds like your lilac has powdery mildew. This is a fungal disease that looks like white powdery substance that covers branches and the upper surfaces of leaves. It can be wiped off. It's caused by spores in the air in warm dry conditions. The typical control for this is to spray you plant with a copper sulfide solution. They are sold in most garden supply stores as folear sprays. Look for the active ingredient being some sort of copper. Remember, with ALL pesticides the label is the law so read and follow the directions carefully. If you do spray, make sure you cover the entire plant, all surfaces. Do it in the morning when the air is calm. For further help contact your local extension office.