Rust and soot on roses »Recognize and fight

Damage and spread of rose rust?

As early as March, shriveled, reddish spots appear on the old shoots. The orange-red spore beds are often overlooked because they are on the underside of the leaf. If the disease progresses, you can see yellow-red spots on the upper side of the leaves from May onwards, which begin to overflow into one another. The spore systems become larger and turn bright orange. If you run your finger over them, you can feel them as distinct pustules.

Rose rust constantly lives on the same plant. The permanent spores overwinter on fallen leaves as well as on the woody shoots and from there attack the new shoots in spring. As soon as an animal touches the pustules on the underside, the fine powder sticks and is transferred to other rose bushes by insects or the wind.

Fight rose rust

Since rust fungi occur almost everywhere and germinate on damp leaves, an infestation cannot be completely avoided. However, you can prevent and strengthen the plant effectively:

• Cultivate varieties of roses that are rust-resistant.
• Give the sticks a sunny, airy place and ensure a loose, humus-rich substrate.
• Water sufficiently in summer.
• Fertilize You with potassium-emphasized special fertilizers, which strengthen the cell walls. These form a natural barrier for the germinating spores.
• As a preventive measure, sprinkle the roses with horsetail broth.

Damage and spread of star soot

In contrast to rust, it forms the sooty rope on the upper side of the leaf large acervuli (fruit beds of mushrooms), which are almost black in color. The conidia in them are widespread through spray water or insects.

The first signs of an infestation appear in April: the leaves of the rose yellow and fall off prematurely. If you do not intervene, the plant will lose almost all of its leaves by summer. Since the metabolism is very limited, the sticks are severely weakened. Hardly any new flowers are formed and new shoots are slowed down. The wood no longer ripens properly and the roses are susceptible to frost damage.

Preventing and combating blackened soot

Prevention is also difficult to prevent in the case of blackened soot because the spores are widespread.

• When buying a new one, look for resistant varieties.
• Always place roses in full sun, airy locations.
• Water only in the root area and avoid wetting the foliage.
• Fertilize with special Rose fertilizerswhose nutrient composition is tailored to the needs of the plants.
• Splash the sticks with garlic or horsetail broth to strengthen them.

Diseased leaves and shoots should be removed immediately with a sharp knife or a knife Rose scissors separate and dispose of with household waste. Then disinfect the tool so that no soot spores remain on it.