Answer: Clematis are occasionally subject to leaf spot problems. If the problem is minor, pick off and remove and destroy infected leaves, and be sure to clean up very carefully this fall after the leaves drop. In more severe cases, a sulphur spray may be used according to the label instructions. In general, improving air circulation can help, too.
Black spot on roses can be a real problem. Some basic steps toward control are picking and removing infected leaves, careful fall cleanup and mulching thoroughly each spring to avoid rain washing it back up onto the plant for yet another season. Improved air circulation, avoiding evening watering and growing resistant varieties can also help.
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