Hawthorn, like many rose plants, is susceptible to fungal diseases. While plants affected by fire blight usually have to be removed, you can fight fungal diseases such as powdery mildew yourself.
What diseases occur in hawthorn?
Hawthorn can be affected by various diseases, such as fire blight, scab, scab and powdery mildew. While fire blight must be reported and usually leads to the removal of the plant, the other fungal diseases can be controlled using pesticides and proper pruning.
Fire blight: Dangerous and reportable
Like firethorn, hawthorn is also susceptible to fire blight. The pathogen is a bacterium that spreads like an epidemic under optimal growth conditions. Fire blight is primarily transmitted through highly infectious bacterial slime, contaminated cutting tools and infected plant material.
You can recognize a fire blight infestation when the leaves and shoot tips of the hawthorn turn brown and dry out; they look as if they were burned. The drooping shoot tips of the affected plant are characteristic. As the disease progresses, infectious bacterial mucus appears on branches and leaves.
If you discover fire blight on a hawthorn, you must immediately report this to the State Office of Agriculture. In most cases, the affected trees have to be cleared. Keeping bees is prohibited in the immediate area because the insects cause the spores to spread over large areas.
Other firethorn diseases:
scab
With this fungal disease, the hawthorn shows brownish spots and cracks on the leaves and fruits. To prevent this, do not plant the hawthorn bushes too closely so that water on the leaves can evaporate quickly. Cut diseased parts back deep into the he althy wood and dispose of the plant parts in household waste.
Grid
The pathogen of this plant disease overwinters on the juniper and attacks the hawthorn again every year. The branches of the hawthorn have orange-colored thickenings in which the spore stores of the fungus are located. Orange-red spots appear on the upper side of the leaves, and the leaf veins and petioles are noticeably thickened. Fight the plant disease with suitable fungicides.
Mildew
Like all rose plants, hawthorn is susceptible to powdery mildew. With this plant disease, the leaves of the affected plant have white-grey, milky spots. As the disease progresses, the foliage curls and the fresh shoots of the hawthorn become stunted.
In dry and warm weather with dew forming at night, the entire plant can be covered by mildew in a very short time. The fungus spreads via spores and forms dark winter fruiting bodies in autumn that overwinter in fallen leaves and fruits.
Remove all affected plant parts and dispose of them in the trash. Then treat the diseased plant with a suitable pesticide.
Tips & Tricks
Fungal spores also stick to garden tools, wooden posts, fences and mats to protect against the cold. Therefore, clean and disinfect all equipment thoroughly after contact with the diseased plant.
