My Hydrangea doesn't look well.☹
My hydrangea's flowers have gotten very small and very pale. They use to be big and blue and I know the soil may be to blame (too alkaline) but they are really light in color and small blooms. Also the leaves look either chewed (maybe slugs) or it's a fungus. I put organic granules around it to keep the slugs away just in case that's what it is, but I really fear it's a fungus and the brutal summer heat is hurting my hydrangea. I water it when it gets dry, I try not to over water, but here lately its been over 95° and it gets very dry. It also gets morning shade and afternoon sun. I fear my hydrangea is dying. Help!
Talbot County Maryland
We notice some leaf scorch (heat damage), wilting of the foliage, and leaf spots, on the hydrangea. The scorch and wilting is due to hot afternoon sun and not enough moisture for the roots. This does not look like an insect issue.
Also, hydrangeas are prone to multiple leaf spots, fungal and bacterial(middle photo). Some fungal diseases are becoming more common on hydrangeas and different cultivars vary in their susceptibility. The damage is cosmetic and will have to run its course.
Fungicides are not recommended as you would have to spray all season.
Avoid overhead watering. Remove any fallen leaves from around the base of the shrub at the end of the growing season. These sanitation practices will help to manage the disease from year to year.
See more on fungal leaf spots https://extension.umd.edu/hgic/topics/fungal-leaf-spots-shrubs
Hydrangeas grow best in morning sun and afternoon shade or dappled shade in a moist well drained soil. Hydrangeas will be stressed in afternoon sun and will require more moisture during dry periods. You will have to water deeply so the soil is moist like a wrung out sponge. Make sure mulch is no thicker than several inches and away from the base of the stems.
At this point we recommend that you transplant the hydrangea in early fall or next spring to an area that receives dappled shade or morning sun and afternoon shade.