Hawthorn Leaf Blight
Hawthorn Leaf Blight
This leaf disease can completely defoliate hawthorn by the end of August.
The disease overwinters in cankers on the twigs as well as on fallen infected leaves.
The first symptom is small brown spots on the leaves. If examined, closely small black spots may be seen in the brown spots. The leaves fall later in the summer. The disease will be worse in wet seasons.
Basic copper sulfate will prevent the leaf drop but is somewhat phytotoxic and causes small spots on the leaves.