Question From: S. Wang - Rockford, Illinois, United States
Q: The flowers on my Oak-leaf Hydrangea are being mutilated by something I am unable to identify. The flowers and stems of the flowers are drying out and turning black. It starts at the top of the flowers and works its way down. There is just a dry brown-black collection of vegetation left where the flower tip was. The leaves are untouched. I have looked all over the internet today and can't find an answer, can you? I suspect aphids but have never been able to find them.
Suzzane, My guess is Boytrytis Blight, also called Gray Mold. Cut off any infected parts back to clean wood. Wipe your pruners with alcohol after every cut. Clean up all debris around the plant . Do not fertilize now, but in late winter or early spring fertilize with Holly Tone at the recommended rate according to package directions. You can spray it with wettable sulfur (availabe at garden centers, every 7 to 10 days. Do not use when temps are over 80 degrees. Hope this helps. Best And Happy Yardening, Nancy