Anthracnose usually leads to death
Anthracnose, also known as leaf tan, which is caused by the harmful fungus Discula destructiva and mainly occurs after very rainy summers, is particularly dangerous. An infestation is noticeable in the initial stage through brown leaf tips and leaf spots and ultimately leads to necrosis on the shoots and twigs. If left untreated, this disease always leads to the death of the infected dogwood, whereby fungicides usually do not help. The only effective method of treatment is in a radical cut back of diseased parts of the plant and that far into the healthy wood.
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Prevent leaf tanning
However, you can prevent leaf tanning by following these rules:
- Carry out pruning measures only in dry and sunny weather.
- Always work with sharp and disinfected cutting tools.
- Always treat larger cuts with a wound closure agent.
- Water when it is very dry.
- Never wet the leaves.
- Avoid over-fertilization - especially with nitrogen.
Powdery mildew can be treated well
The real mildew - also known as "fair weather mushroom" - occurs mainly in warm and sunny weather and is noticeable through a greasy, greyish-white mushroom lawn on leaves and shoots. Fortunately, this plant disease can be combated very well, and not only fungicides have proven effective. Instead, you can mix the dogwood with a mixture of (low-lime, but not necessarily rainwater!) Water and spray whole milk in a ratio of 10: 1, this measure being carried out for several days in a row should. Infested parts of the plant should be cut away generously and disposed of with household waste.
Make mealybugs harmless with rapeseed oil
Mealybugs can often only be recognized when the whole horn bush is stuck and countless ants have gathered on it. The stubborn miniature animals suck off the leaf juice and excrete a sweet liquid, the honeydew. The control takes place either biologically Parasitic wasps(€ 69.90 at Amazon *) respectively. Earwigs - the natural enemies of mealybugs - or by regularly spraying the entire bush with rapeseed oil.
Tips
The powdery mildew hibernates on the leaves that have fallen in autumn, so that the fungus can attack the dogwood again in the following spring. Therefore, after an infestation, you should always rake up all the leaves and dispose of them - of course not on the compost.
