Dwarf rose

Question: dwarf rose

I have a little dwarf rose for about 3 years, every spring produces new leaves but at the same time the other leaves make dark spots and then fall, so the plant does not grow and remains very small without flowering. can you tell me what i can do?

Answer: dwarf rose

Gentile Morena,
probably your rose is attacked by a fairly common fungal disease on roses, the scab. This parasite manifests itself with dark, sometimes black, round spots, which develop rapidly on the leaves, ruining them conspicuously until they dry out; the infected leaves will be completely lost from the plant, which sometimes remains almost without any leaves. Generally the scab tends to develop preferably during periods that are not excessively hot, and quite humid, and therefore in spring and autumn; when the heat arrives, the new leaves produced by the plant are unlikely to be infected, and the disease tends to be underestimated. Unfortunately, as with so many fungal parasites, these are very resistant, and remain on the ground even in conditions unfavorable to their life. In essence, the diseased leaves fall, the fungi on them release their spores on the ground; the spores await a period with the best climate, and begin to attack the new leaves. So, if you do not cure the disease when it is present, you are destined to see it again from year to year on your little rose. Since it is a single plant, the first thing to do is to remove all the leaves affected by the black spots and burn them; in addition to this, if you fear that the scab has recurred, try treating the plant with a systemic fungicide at the end of winter, or with the Bordeaux mixture (copper plus sulfur), in order to kill the disease in the bud. But, if you remove the leaves in spring, and then again in autumn, following this with a vigorous pruning of the plant, it is probable that the disease does not develop the following year; in any case, at least the first year, you can practice a preventive treatment at the end of winter, with Bordeaux mixture.