If traces of rust are visible on your roses , it means that it is too late to fight it. This fungal disease is very difficult to cure, one way or another you will have to take drastic measures and be uncompromising – because the longer you delay the treatment of your bushes, the more irreversible will be the weakening effect of the fungi that cause this disease on them.
The first step in the fight against rust should be timely diagnosis. The sooner you identify lesions, the less damage will be done to your roses. Because rust has no latent incubation period and appears immediately on stems and young leaves as rusty spots and bright orange pads on the inside of leaves (true rust) or in mid-season as black spots on the outer surface of green leaves (black spot) – it is very easy to spot. Regular examination will allow you to notice the first symptoms of the disease and respond in a timely manner.
Affected leavesburn it (even if only one spot is visible on them!), and if there are spots on the trunk, cut it as low as possible. Next, spray the bush with preventive mixtures to prevent the spread of the disease. After removing all damaged parts of the plant, be sure to spray the bush with soapy water. The fastest way is to dissolve a bottle of liquid soap in a bucket of water, but this method is effective in combating aphids, while toilet or laundry soap (buy a simple domestic baby soap or a bar of soap with a high alkali content at the pharmacy) fights rust much better. Two bars of soap must be dissolved in a bucket of hot water, cooled – and the spray mixture is ready. Rose bushes are sprayed with it, trying to go through the underside of the leaves twice a week until the threat of rust disappears. Protecting your roses from rust should always be focused on prevention, because it is almost impossible to cure plants from this difficult fungal disease. Next, the soap solution should be replaced with a decoction of nettle or horsetail or a specialized remedy for roses – sistan. If in the summer you find black spot, then you should resort to more serious measures – spraying with fungicides.
You will be able to completely get rid of rust only if you get rid of aphids and mealybugs that parasitize on the affected plant. If after all the treatments you still notice aphids, wash them off with a strong stream of water and re-spray with soapy water.
Inventory should be thoroughly washed after each use when spraying, and disposable gloves should be used. If you use cloth gloves, be sure to wash and boil them after each treatment of the bush with both soapy water and prophylactic products.
Even if you get rid of the rust and no longer find traces of it on the leaves, in the fall the affected bush should be , leaving the shoots at the level of the third bud from the soil surface. Try to replace any topsoil that may have retained fungal spores, or spray the soil with rose preparations, and then lay down fresh mulch.