Boxwood is a classic victim of fungal pathogens. In some cases, the best care is of no help and the carefully tended wood still gets brown leaves and shoots. However, this does not necessarily mean the death sentence, because some fungi can be effectively combated with a courageous pruning and the right fungicide.

A fungal infestation should be treated promptly

Typical fungal infections in boxwood

There are a number of harmful fungi that exclusively or preferentially attack boxwood. These include the following candidates:

  • Cylindrocladium buxicola: also known as the boxwood fungus, causes the dreaded dieback of shoots
  • Volutella buxi: causes box tree cancer, resulting in shoot death
  • Puccinia buxi: causes boxwood rust, recognizable by red-brown pustules on the upper side of the leaf

Characteristic features of every fungal disease are leaves and shoots that turn brown and dry up, with the leaves and shoots often only showing yellowish to brownish spots in the initial stages. Usually not the whole boxwood is affected, but only a part of the branches and shoots. Depending on the pathogen, white to reddish-brown spore deposits can be found on the underside of the leaves when the infestation is advanced.

Avoid fungal infection effectively - you have to do that

Since almost all fungal diseases occur as a result of damp and warm weather, you should take precautionary measures when the weather is appropriate:

  • Always water box trees from below, never over the leaves!
  • If possible, leaves should not be permanently damp.
  • Never cut in the rain or damp weather!
  • This is when the risk of infection is highest in otherwise healthy plants.
  • Keep boxwood moist but not wet.
  • Too moist soil and waterlogging inevitably lead to root rot.

Since weakened plants are also more likely to be infected, you can strengthen your box trees with optimal site conditions and species-appropriate care. Above all, pay attention to a balanced supply of water and fertilizer - in addition to a lack of nutrients, over-fertilization can also have serious consequences. Furthermore, an airy, sunny location is ideal, and by observing the recommended planting distance you can do a lot to keep your bush healthy.

Effectively fight fungal infestation - Here's how

However, once the box has been attacked by a fungus, the only thing that can usually help is scissors. Generously cut out the diseased parts of the plant, whereby even severe pruning does not harm the box. It just takes a long time to get back to its original size and shape due to its slow growth. Fertilize the plant to stimulate new growth, and you can also treat it with home remedies against the fungi. A self-made field horsetail broth has proven to be effective. If the measures mentioned do not help, the only option left is the use of chemical fungicides - which need to be carefully considered in the home garden due to the side effects! - or the clearing.

tips

If there is a white to greyish, wipeable coating on the upper side of the leaves, it is probably powdery mildew. This occurs - in contrast to other fungal diseases - in bright sunshine and heat, which is why it is also referred to as "fair weather fungus". You can get this infection under control by treating the affected box trees with a mixture of fresh whole milk and water (ratio 1:10).

Category:

Vegetable garden