As beautiful as the "Queen of Flowers" is, she is prone to fungal infections.

Brown spots on roses are usually the result of fungal diseases

Fungal infections cause brown spots on roses

Brown spots on leaves or shoots are usually the result of a fungicidal disease, for which various pathogens come into question. The treatment is carried out by a vigorous pruning, in the case of a severe infestation, spraying with fungicides is often necessary. The vast majority of mushrooms feel particularly comfortable in damp weather, which is why roses should always be in an airy location - there the leaves can dry faster in the rain.

Wrong mildew

Downy mildew is noticeable by rust-red spots on both the leaves and the shoots. The problem with downy mildew is the fact that the pathogen fungus Peronospora sparsa penetrates very deeply into the tissue and is therefore difficult to combat.

rose rust

Rust fungi cause leaf chlorosis (i.e. the foliage turns significantly lighter to yellowing) and rust-colored spots on the leaves. The affected leaves die and are eventually shed, and the whole plant is severely weakened.

blackspot

The leaves can also turn yellow if infected with Diplocarpon rosae, the causative agent of soot. More typical, however, are the very dark, rather black spots, which become larger and larger as the disease progresses. Diplocarpon rosae mainly spreads the flight spores.

Leaf and stem base rot

This disease is caused by the fungus Cylindrocladium scoparium, which initially causes brown spots on the leaves and soon kills them. In addition to the leaves, shoots and roots can also be affected, which eventually begin to rot as the infestation progresses.

bark spot disease

The main cause of the bark blotch disease is a strong nitrogen fertilization of the roses. The brown to reddish-purple spots appear mainly near shoot buds.

Prevention is better than cure: plant hygiene is particularly important

Since fungal diseases are very difficult to fight - after all, the pathogens penetrate deep into the plant tissue and can only be removed by a courageous cut down to the healthy wood - you should better prevent an infestation. This not only includes spraying susceptible rose varieties with pesticides in the spring, but also observing the basic rules of plant hygiene. Leaves - both those that have fallen off and those that are still on the bush - should always be disposed of in autumn, as the fungal spores overwinter on them and thus ensure a new infection in the following spring.

tips

Regular pruning and thus rejuvenation of the rose bush is just as important as removing the foliage. The cutting tool should always be sharp and well disinfected - preferably with high-proof alcohol.

Category:

Vegetable garden