My hydrangea leaves have brown/black spots on them every year. Other species I have do not do this. Try not to water plants just roots. Can you help me figure out what is wrong and what I can do to fix.
Are your hydrangeas in a place where they are crowded or have poor air circulation? That can cause problems with leaf spot. It’s good that you are watering at the base of the plant rather than overhead. That will help. Also, at the end of this year, gather up all the fallen leaves and throw them away rather than compost them. Then, put down fresh mulch. In the spring, look at thinning the plant so the branches aren’t tightly packed and increase air flow. Following these tips should help reduce leaf spot fungus next year.