How you can recognize the disease quickly and treat the boxwood fungus, as well as information about pesticides and whether home remedies help.
The boxwood owners among us have indeed not had it easy for a number of years. The invasive boxwood moth eats up entire stands of boxwood if there is no timely action. Since 2004, however, a completely different pest has been causing major problems. The death of shoots in the Buxus genus, triggered by the harmful fungus Cylindrocladium buxicola, is causing big problems in northern Germany, but also increasingly in the south. Since boxwood can also be attacked by other fungi, it is important to identify the symptoms precisely.
contents
- Recognize boxwood fungus
- Boxwood mushroom: a profile
- Prevent boxwood fungus
- Fight boxwood disease
Recognize boxwood fungus
The first signs of infection with C. buxicola are leaf discoloration or Leaf wilt. Young leaves turn orange-brown and old leaves only have brown spots. Depending on the severity of the infestation, the leaf spots can grow quickly and whole shoots are quickly infected. However, the leaf spots in themselves are not yet a reliable identification feature. Only when you can see small black stripes on the infected shoots, which can be seen from below spread to the tip of the shoot, you can be sure that it is the shoot death acts. In the further course of the disease there is usually strong leaf fall, combined with the death of entire shoots and in the worst case the whole boxwood dies.
Boxwood mushroom: a profile
The pest presented here does not need open wounds to overpower the boxwood. If the leaves of the Buxus are wet for at least 5 hours, the fungus can grow into the healthy leaf tissue and the infection can no longer be stopped. If the fungus finds good growth conditions (25 ° C), the characteristic symptoms can be seen one week after the first attack. However, if the temperatures are consistently well above 25 ° C, then this is not good for the fungus. A hot summer can therefore significantly limit the infestation. In addition, the mushroom forms C. buxicola so-called permanent spores. These can persist in the soil for at least 4 years and infect the beech tree plants again. The fungal spores are spread by wind, water splashes and of course via trade and infected cuttings.
Prevent boxwood fungus
It is essential that all measures to prevent boxwood fungus are fully exhausted, as shoot death is very difficult to combat. The first thing you should try is to keep your book trees as dry as possible above ground. Because if the leaves dry off quickly, the fungus has less time to germinate and thus to infect the plant. So look for a sunny and airy location for your box trees - the leaves can dry out more quickly there. In addition, the boxwood likes an even supply of water. When watering, however, make sure that only the soil gets wet and not the leaves.
The choice of variety can also help avoid shoot death. In general, vigorous boxwood varieties should be less susceptible, including, for example, the varieties “Herrenhausen”, “Faulkner” and “Brno”. Unfortunately, there are still no completely resistant varieties. In the case of already infested box trees, a radical pruning into the healthy wood can help, but there is no guarantee of success. It is important that the cut shoots do not end up on the compost. Because of the problematic permanent spores, all cutting waste belongs in the residual waste. It is also advisable to remove the top layer of soil under a diseased Buxus. There the earth is enriched with falling permanent spores. Despite these measures, it is not necessarily advisable to plant a new box tree directly on the spot where an infected box tree was previously.
Fight boxwood disease
As mentioned earlier: An effective control of the boxwood disease is very difficult. The harmful fungus cannot be combated as soon as it has penetrated the boxwood. An additional problem is the enormous resistance of the fungus. So far we have not been able to find any reliable information that confirms that home remedies or biological sprays are effective against the fungus. So it is not possible C. buxicola to be treated with natural or biological preparations.
Even the chemical club only works with a preventive spray. In practice, this would mean that you would have to prophylactically mist your box trees with fungicides after every rain in the gardening season. In the end, everyone has to decide for themselves whether this is the right way for the hobby gardener. In the case of heavily infested box trees, only the complete clearing of the diseased plants often helps, even if there are no substitute plants with a similar appearance. One can only hope that breeders will quickly develop resistant varieties or find new methods of combating the harmful fungus.
Algae lime against boxwood disease
For some time now, more and more of our readers have been reporting on the successful fight against boxwood disease. of the mushroom Algae lime. You spray the box plants between the end of April and the beginning of May Algae lime, a clear recovery of the plant can be seen within a few months. The treatment should also be used against the boxwood moth and its eggs Algae lime help.
Boxwood fungus isn't the only problem boxwood owners struggle with. Even the annoying one Box tree moth is probably known to most hobby gardeners. We will introduce you to the pest and explain how you can fight it.
Special thanks to the photographer: Dr. Thomas Brand.
