Answer: Hydrangeas are subject to a number of bacterial and fungal diseases, but your plants might also be victim to sucking insects which can cause curling and crinkling of leaves. Try unrolling one of the leaves to see if you can find evidence of insects, a sticky substance, or even the cast skins of aphids. Use a magnifying glass to get up close and personal with the leaf. Bud blight (Botrytis cinerea) occurs during wet weather and turns the buds a tan or brown appearance. Root rot (Pseudomonas) also causes a blighting of blossoms and a wilting of leaves. This is apt to happen after extended heavy rains that saturate the soil and smother the roots. If none of the above descriptions seem to match the problem with your hydrangea, why not take a sample to your local Cooperative Extension office for positive diagnosis? Contact Cornell University Cooperative Extension, Bldg. J., 1425 Old Country Rd., Plainview, NY 11803-5015. Phone (516) 454-0365.
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