Q: My hydrangea bloomed white but instead of turning red it turned brown. What is happening to the petals and what can be done?
A: A disease called Botrytis blight can cause spots and browning symptoms on the flower petals of Hydrangea and other types of flowers as well. Extended periods of cloudy, rainy weather like we had recently can favor the development of this fungal disease. Botrytis first appears as water-soaked spots that gradually expand into brown blotches. There is no remedy for this damage. Prune out and dispose of the damaged flower parts.
The spotting on the leaves is common on Hydrangeas in late summer, especially in our humid climate. Leaf spots can be caused by fungal and bacterial pathogens. The leaf spots are mainly a cosmetic problem. They will not kill the plant. Chemical control is not recommended in most home garden situations.
Keep Hydrangeas watered regularly during drought periods and avoid overhead watering to minimize wetness on the flowers and foliage. Clean up and dispose of symptomatic leaves at the end of the growing season.
Visit the Home & Garden Information Center website for more information on common problems of trees and shrubs.
By Christa K. Carignan, Coordinator, University of Maryland Extension Home & Garden Information Center
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