What Diseases And Problems Are Hydrangeas Prone To?

          Mites and aphids.

          Root rot if over-watered or poorly drained.

          Japanese beetles and deer feed on hydrangeas.

            Bacterial blight can cause flowers and leaves to wilt.  This is a problem in very hot and very wet locations.   The actual culprit organism is Pseudomonas solanacearum.  There is no treatment for this; hydrangeas are just not suitable for certain climates.


            Grey leaf spots may appear on hydrangeas due to funghi.   In a severe form this leds to powdery mildew, which must be treated with fungicides.  A milder problem are from another fungus, Rust spots appearing on leaf undersides.  These eventually cause leaves to curl up and die, thankfully usually near the end of the growing season.  


            All fungal problems are more likely when a plant has too much sun and too much water on the leaves (better to apply water only to roots).


            Botrytis cinerea can cause blight in dense flower clusters after a frost or a prolonged rainy period.


            Big yellow spots on leaves indicate an iron deficiency in the soil.


            Too cold conditions may cause the plant to never flower (blooms killed by frost).

The green leaves are falling off my hydrangea

White bug on underside of leafs and on stems