Roses are always attacked by fungi. We will introduce you to the most common fungal diseases and show you how to treat them.
A garden without roses is hard to imagine. It is all the more annoying when their beauty is destroyed by diseases. Powdery mildew, downy mildew, rose rust and blackspot are particularly annoying hobby gardeners by spreading on the roses. These are leaf diseases caused by a fungus. There are certainly things you can do to prevent an infestation from occurring in the first place, but sometimes it's just too late. Then it only helps if you act quickly.
❖ Powdery mildew:
These mushrooms stop at no rose. If roses are affected by this fungus, the shoots and leaves are covered with a white coating. The leaves then turn brown, curl up and fall off. The fungus spreads rapidly, especially in dry and warm weather combined with night dew.
Combat:
Infected areas should be generously removed immediately. Then mix one part whole milk with eight parts water, put it in a spray bottle and spray the affected roses with the mixture once a week. The microorganisms in the milk not only fight the fungus, they also help the rose build up a kind of resistance to the fungus.
Alternatively, you can also spray the infested plant with garlic broth or nettle manure. Also look out for more resilient varieties when planting.
❖ Downy mildew:
The leaves get reddish-brown spots on the upper side. As a result, mold forms. Also with this disease the leaves fall off. In addition, the buds often dry up.
Combat:
First remove all affected parts of the plant. In particularly severe cases, it may even be advisable to remove the entire plant from the garden. This will prevent the fungal disease from spreading to other plants. You can also spray the roses with a mixture of milk and water for this type of mildew. A decoction of field horsetail, which you use every other day, also helpsto spray on the plant. To do this, soak 1 kilogram of horsetail in 10 liters of water for 24 hours and then boil for 30 minutes.
❖ Rose Rust:
This disease manifests itself in red or yellow spots on the upper side of the leaves. On the underside of the leaf, however, are the spore bearings. Dark spores later escape from this, which are scattered by the wind and spread to other plants. If the infestation is severe, the rose sheds its leaves.
Combat:
Remove infected foliage immediately. You can then spray the roses every two days with horsetail decoction. If that doesn't help, you'll need to use a fungicide. We recommend, for example, CELAFLOR rose-fungus-free Saprol. It is best to always follow the manufacturer's instructions when applying.
❖ Blackspot:
This fungal disease causes irregularly shaped grey-black spots on the leaves. In addition, the rose petal is always yellowish in color near the spots. If the infestation is severe, the roses will even shed their leaves.
Combat:
Remove all affected parts of the plant and also the leaves that have already fallen off. The fungus overwinters in the leaves on the ground and thus spreads further. You can then spray the roses with garlic stock or horsetail stock. If that doesn't help, you need to use a fungicide. Again, you can fall back on CELAFLOR rose fungus-free Saprol. But COMPO Duaxo roses are fungus-free just as well. Again, follow the manufacturer's instructions.
Important: Dispose of infested plant parts in the residual waste
Always dispose of the infested plant parts with the residual waste, because fungi can overwinter in the plant parts and spread further in the garden. Therefore, never put the affected parts on the compost. Also clean all garden tools and planters. This also applies to trellis, privacy fences, etc.