Chrysanthemums: Identifying and avoiding pests and diseases

Even hardy and hardy plants like chrysanthemums can be attacked by pests and diseases. But 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 care can spread pests on the plant. Anyone who reacts quickly and treats the pest infestation or the disease has a good chance that the chrysanthemum will recover.

Spider mites on chrysanthemums

The tiny spider mites are barely visible to the naked eye. Regularly check the underside of the leaves - if there is a whitish web here, then the spider-like, yellow, green or red little creatures are at work.

Combat:

➔ If the infestation is low, spray the plant with a biological agent based on rapeseed oil. We can recommend the Naturen Schädlingsfrei (e.g. available here). The oil clogs the respiratory organs of the spider mites and prevents further reproduction. Pyrethrum-based sprays also help.

➔ Wrapping it in foil can also help. Spray the chrysanthemum liberally with water and wrap the visible part of the plant in foil. Damp heat builds up in the foil. The spider mites cannot tolerate this and are destroyed. However, the film treatment takes about two weeks.

➔ If the infestation is extremely severe, it is worth purchasing predatory mites. The PP predatory mites eat spider mites and naturally ensure that the plant is rid of the pests. When using predatory mites, a humid climate should also prevail - the temperature should be above 18°C during the day.

Leaf spot on chrysanthemums

If you spot yellow, reddish or brownish spots on the chrysanthemum leaves, the plants have contracted a fungal disease. To prevent this from happening in the first place, you can spray a tea infusion made from onion skins or horsetail as a preventive measure.Many chrysanthemum species are largely resistant to fungi, but unfortunately there is no such thing as 100% protection.

Leaf spot is caused by various fungi, such as Septoria, Alternaria and Ascochyta. The fungi settle on the underside of the leaves with their fruiting bodies, and the spots appear on the upper side of the leaves. If the propagation is high, the leaves look perforated, which is referred to as "shotgun disease".

Combat:

If only individual parts are affected, remove them generously. Disinfect the secateurs with alcohol after each cut so that no further fungal spores can spread and multiply. Unfortunately, biological control or home remedies are not effective.

Treat heavily infested plants with an antifungal agent. Broad-spectrum fungicides are particularly well suited, as they often involve a combination of several types of fungi.

» The only alternative: Separate yourself from the plant. But please don't throw them in the compost heap!

Prevention: site selection and care

Dry, bright and sheltered from the wind, this is the ideal location for chrysanthemums. If you plant several perennials, make sure there is enough space between them. Dry foliage protects against fungal attack, so only water chrysanthemums from below.