Hydrangea leaves

Hi Elizabeth,

There are several reasons why hydrangea leaves turn brown and curl. Insects, disease, and growing conditions can all result in brown, curled foliage. Hydrangea are a large group of plants, and some viruses only affect specific cultivars. Stressed plants are more susceptible to insect/disease issues. My first thought is that this is a result of the hot and extremely dry conditions but without having a sample, it is simply a guess. The only way to know for sure what is going on with your shrubs is to have a sample analyzed. The horticulture agent at your County Cooperative Extension Service will be an excellent resource for you. They will be able to look at your sample and tell you why this is happening and give recommendations for treatment.