|I have dark spots on my hydrangea leaves. The flowers are a very dull pinkish. Do I need something for the soil?
|Answer from NGA
June 30, 2010
|Dark spots can indicate a fungal disease so I think a fungicide is in order. Use a general purpose fungicide and spray both the upper and lower parts of the leaves. Hydrangea flowers can turn pink in alkaline soils. You can change the soil's pH but it takes several months. Start your soil treatments early next spring by treating the soil with 2 Tablespoons of aluminum sulphate per plant, making 4-6 applications at 2 week intervals, starting in the early spring before the plants bloom.
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