Patient hobby gardeners like to enjoy a box tree in their own garden. It is all the more annoying when a disease suddenly occurs that damages the already slow-growing boxwood. The boxwood fungus is one of the most stubborn diseases that is difficult to combat. But there are ways and means to prevent and treat the infestation.
What is the boxwood fungus?
This fungus is the Cylindrocladium buxicola fungus - a pest that can lead to acute shoot death.
This disease was first identified in 2004 and since then more and more trees have been affected. Whether in the private sphere or in public green areas - the dieback is spreading and can be easily recognized even by laypeople in the late stage.
Identify boxwood fungus
In the case of a heavily infested boxwood, visual diagnosis is completely sufficient. Dark brown, partly light brown ones form stains, which spread on the leaves. These spots merge into one as the disease progresses.
The shoots of the tree show black stripes, only then does it spread to the leaves. These fall off as the disease progresses and eventually this begins dieback.
If left untreated, the boxwood fungus will spread so far that the entire tree dies and can no longer be saved.
The symptoms at a glance
- Shoots have black stripes
- Leaves are mottled brown
- the spots spread and close together
- Leaves begin to fall
course of the disease
In order for a boxwood fungus to develop at all, the leaves have to dry over a long period of time wetness be exposed. Only after a period of at least five hours, the boxwood fungus can develop.
It then takes about a week before the boxwood fungus can be identified. The first spots show up quickly. The leaves can already fall around four weeks after the first infestation. The boxwood fungus is extremely resistant because it develops so-called permanent spores that can survive for up to four years and thus promote the disease.
Fight the boxwood fungus
the leaf moisture is one of the main risks in the formation of the boxwood fungus. The more this moisture can be avoided, the lower the risk of fungal infestation. However, free-standing trees are difficult to reliably protect against liquids.
When choosing the location, it is advisable to pay attention to a sunny, windy location, as this will dry the leaves faster when it rains.
If the boxwood has to be watered manually, you should only water the root and trunk, not the foliage.
Acute infestation - how to act?
It is not always possible to fight the fungus. If the infestation is severe, the tree must be disposed of. It is important here that all parts of the plant either have the residual waste or by combustion be eliminated.
The top layer of soil must also be disposed of, as the fungus can nest here for many years and spread to other trees.
If the boxwood with the help of tools removed or circumcised, they must be thoroughly cleaned due to the risk of infection disinfected will. A transfer to other trees is otherwise easily possible.
Tips for action in the event of a high infestation
- Remove and destroy affected plants
- completely remove the top layer of soil
- do not plant new box trees
- Disinfect and clean tools
Spray used against the fungus
Injectables are hardly sufficient as a treatment method, they are more used for prevention. The boxwood fungus is extremely stubborn, fungicide sprays are no longer sufficient for treatment.
However, it is advisable to work with a suitable fungicide for prevention.
The following active substances are possible:
- azoxystrobin
- difenoconazole
- Tebuconazole
Fungicides and similar agents are a good way to avoid an infestation to prevent. It is then advisable to spray the plants before any symptoms have appeared. If an infested box tree was nearby, it is even very important to spray to prevent the fungus from spreading.
Algae lime as the means of choice
While most sprays are unsuccessful in combating the boxwood fungus, more and more hobby gardeners are pinning their hopes on algae lime. The calcareous fertilizer can a pH improvement of the soil and possibly controlling the fungus. Preventive fertilization with algae lime enormously limits the chances of the boxwood fungus spreading.
Even in the early stages of infestation, treatment with algae lime can still be promising. It is definitely worth a try before you have to dispose of the plant.
Algal lime as fertilizer
Recognize the dieback as early as possible
If you have a box tree in your garden, it is very important that you protect it check regularly. You should pay attention to the typical symptoms of the fungus when you buy it, so that you don't accidentally put a diseased tree in your garden.
In the early stages, the fungus can be attached to the leaf undersides detect. As a suitable remedy, you should use a magnifying glass to look for whitish deposits that represent the spore store of the fungus.
A short time later, black stripes develop on the shoots and the leaves get the typical spots. At the time when no spots have formed but the fungus is already active, you can possibly save the plant with algae lime.