Even robust and resilient plants like chrysanthemums can be attacked by pests and diseases. If you react in time, you can help the plant.
Chrysanthemums originally come from Asia and are among the most important ornamental plants. A main reason for the high level of popularity is the ease of care and the robustness of the plant. Nevertheless, it can happen that small mistakes in the care pests spread to the plant. If you react quickly here and treat the pest or disease, there is a good chance that the chrysanthemum will recover.
Spider mites on chrysanthemums
The tiny spider mites are barely visible to the naked eye. Check the undersides of the leaves regularly - if there is a whitish web here, then the spider-like, yellow, green or red animals are at work.
➔ If the infestation is low, spray the plant with a biological agent based on rapeseed oil. We can recommend Naturen Pest Free (e.g. available here). The oil sticks to the respiratory system of the spider mite and prevents further reproduction. Pyrethrum-based sprays also help.
➔ Wrapping in foil can also help. Spray the chrysanthemum liberally with water and wrap the visible part of the plant in foil. Moist heat forms in the film. The spider mites cannot tolerate this and are destroyed. However, the film treatment takes about two weeks.
➔ If the infestation is extremely strong, it is worth buying predatory mites. The predatory mites eat spider mites and naturally ensure that the plant is freed from the pests. When using predatory mites, there should also be a humid climate - the temperature should be above 18 ° Celsius during the day.
Leaf blotch disease on chrysanthemums
If you see yellow, reddish or brownish spots on the chrysanthemum leaves, the plants have caught a fungal disease. To prevent this from happening in the first place, you can spray a tea infusion with onion skins or field horsetail. Many types of chrysanthemum are largely resistant to fungi, but unfortunately there is no one hundred percent protection.
The cause of leaf blotch disease is various fungi, for example Septoria, Alternaria and Ascochyta. The mushrooms settle on the underside of the leaves with their fruiting bodies, on the top of the leaves the spots appear. The leaves look perforated when they multiply rapidly, which is then referred to as “shotgun disease”.
If only individual parts are affected, remove them generously. Disinfect the secateurs after each cut with spirit so that no further fungal spores can spread and multiply. Biological control or home remedies are unfortunately not effective.
Treat heavily infested plants with an anti-fungal agent. Broadband fungicides are particularly well suited, since they are often a combination of several types of fungus.
»The only alternative: separate yourself from the plant. But please do not dispose of them in the compost heap!
Prevention: choice of location and care
Dry, bright and protected from the wind, this is the ideal location for chrysanthemums. If you plant several perennials, make sure there is enough space. A dry foliage protects against fungal attack, so only pour chrysanthemums from below.