|My clematis jackmani is developing some kind of leaf spot. The leaves near the base of the plant and some near the middle are turning pale green with dark spots. On the other side of the fence directly behind it is my neighbor's climbing rose which is seriously infected with black spot. Is this the same disease and how do I get rid of it? I would prefer an organic method if possible.
|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.