What Causes Purple Spots on Hydrangea Leaves

Cercospora Leaf Spot is caused by the fungus Cercospora hydrangeae. These are generally small spots, starting as small purple or tan spots at the base of the plant. As the disease progresses the spots will move up the plants, affecting most of the leaves.

How do you treat spots on hydrangea leaves?

Leaf spots To control leaf spot, avoid watering your hydrangeas from overhead, and again, remove and destroy diseased plant parts. If summer rains make the problem worse, try a fungicide such as Immunox (always follow label directions).

Why are the leaves on my hydrangea turning purple?

Most commonly, it’s a phosphorus deficiency that can cause a purple coloration of the leaves. Phosphorus deficiency can appear as a result of a soil pH disbalance. … A pH meter can help you make sure you’re not overdoing the acidification and cause your hydrangea leaves to turn purple as a result.