Spots on hydrangeas
The hydrangeas look like they were subject to some old leaf spots. Leaf spots can be common in wet seasons such as this past spring. Hydrangeas and different cultivars vary in their susceptibility. We have gotten several reports of this.
Fungicides are not recommended as you would have to spray all season. Avoid overhead watering and remove heavily spotted foliage during the growing season. This is not practical if most of the leaves are affected. Simply 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.
Hydrangeas prefer dappled shade. Water the hydrangea during dry periods. Water deeply and let the soil dry slightly before watering again.
You can prune any
brown foliage or flowers. If they still have green tissue leave them. They will continue to photosynthesize thru fall.