The hollyhock is actually quite robust, but rust fungus is a constant threat to its beauty. It causes the dreaded mallow rust and should definitely be combated. Since he is very stubborn, you need some patience.
What diseases occur in hollyhocks?
The most common diseases of hollyhocks are mallow rust, caused by the fungus Puccinia malvearum, and wilt caused by fungi. Mallow rust can be treated, such as removing infected leaves or using fungicides, while wilt is usually fatal.
What diseases does the hollyhock suffer from?
Mallow rust occurs most frequently on hollyhocks. It is caused by the fungus Puccinia malvearum. But another disease can also occur, wilt. It is also caused by fungi and, depending on the pathogen, affects different parts of the plant.
The fungi destroy the hollyhock's water vessels and usually cause the plant to die. If there is an infestation, dig up the affected hollyhock and destroy it. Treatment for this plant disease is not possible. To prevent infection of newly planted hollyhocks, also remove the soil around the affected plant.
The treatment of mallow rust
In contrast to wilt, mallow rust can definitely be controlled. If only individual leaves are affected, cut them off and dispose of them with household waste. Never put plant parts infected by fungi in the compost; the spores could survive there and attack other plants when the compost is spread.
If the infestation is severe, a fungicide can be helpful. If you would rather do without chemicals, the only solution is to destroy the sick hollyhock and, if you replant it, to prevent infestation.
How to prevent it
The sooner you prevent it, the less you actually have to do. Plant your hollyhocks in a location that is as sunny as possible with nutrient-rich and, above all, permeable soil. Be sure to keep a sufficient distance between the individual plants, about 40 cm is recommended.
Water your hollyhocks regularly and give them the necessary fertilizer, the poorer the soil, the more often. Spray your hollyhocks with a horsetail broth or compost broth to support their resistance.
Preventive measures against diseases:
- sunny location
- nutrient-rich soil
- don't plant too close together
- water regularly
- fertilize sufficiently
- Horsetail broth or compost broth
Tip
In a sunny location and well supplied with nutrients, your hollyhock should be resistant to diseases and pests.