The most common are powdery mildew, botrytis, leaf spot and root rot. For powdery mildew, it is essential to promote air circulation and avoid wetting the leaves.
If we know that our plant falls victim to this disease every year, it is advisable to intervene after spring rains by spraying sulfur. If the attacks are particularly severe, they can be treated with specific products.
For botrytis and leaf spot, water stagnation must be avoided and, if necessary, suitable fungicides should be applied. For root and crown rot as well, the primary advice is to absolutely avoid water stagnation.
If they do appear, you can try to contain the problem by cleaning the base and spraying copper-based or specific products. However, if the infection is widespread, it is best to uproot the specimen and restore the area by completely replacing the soil.
Hydrangeas can also be attacked by insects. In these cases, it is advisable to intervene with contact insecticides (for aphids) or systemic insecticides combined with mineral oil (in the case of scale insects).
