Fungi, viruses, bacteria or pests: the once popular boxwood is threatened on many fronts. In addition to the box tree moth, which is difficult to combat, a certain fungal infection in particular causes problems for many box tree stands. But the dreaded dying of instincts does not have just one cause.
The dieback is caused by a fungal disease
Warm, humid weather favors fungal infection
When it gets warm and humid in summer, the fungal infections are at their peak. Once Cylindrocladium buxicola has settled in, the gardener first notices brown spots on the leaves of the boxwood that quickly become larger. The underside, on the other hand, shows many tiny white dots. These are the spores of the fungal pathogen. As the disease progresses, the leaves fall off, and the shoots die and remain as dried-up, brown skeletons.
You can do that
Since effective pesticides are not permitted in allotments and home gardens, you only have scissors: cut out affected areas generously and prune back large box trees vigorously. Do not wait too long with such a cut, because the disease progresses quickly. If the plants are still quite small, only clearing will help. It also makes sense to remove the top layer of soil around the affected plant and replace it with healthy soil - the fungal spores overwinter in the soil, but also in the plant material. Therefore, carefully sweep up the clippings and fallen leaves and dispose of them with household waste.
Effectively prevent dieback
Since an infection with Cylindrocladium buxicola occurs during a rainy phase and the boxwood leaves have to be exposed to strong moisture for at least several hours, you can prevent it with a few simple measures:
- If necessary, always water boxwood from below, never from above!
- The leaves must not be wetted.
- Plant the shrub in a location that is as sunny and airy as possible.
- Make sure there is sufficient planting distance, do not plant a hedge too densely.
- You can also cover valuable solitaires to protect them from moisture.
- Dust your boxwood with fine algae lime.
The most important precautionary measure, however, is this: Never cut your boxwood when it is raining, because then the fungus has an especially easy hand due to the open cuts.
These pathogens also cause shoots to die off
In addition to Cylindrocladium buxicola, there are other pathogens that cause similar symptoms:
- Volutella buxi: causes boxwood cancer, especially young leaves and shoots are affected
- Fusarium buxicola: Boxwood wilt, often only individual shoots are affected
These are all fungal diseases. A virus infection, on the other hand, is rare in boxwood. However, there is another dreaded animal pest that also triggers dieback and eats entire stocks bare within a very short time. We are talking - how could it be otherwise - of the box tree moth, a butterfly whose caterpillars have a great appetite for boxwood.
tips
In the event of an infestation with the box tree moth, you don't have to resort to the chemical club right away. There are effective home remedies that are non-toxic and easy to use.