Even if a tree may appear he althy on the outside, it may already be rotting on the inside and therefore at risk of collapse. For this reason, you should check your trees regularly to avoid unpleasant surprises. Only then can you intervene in time - which is especially important if the tree is on public land and can cause serious damage if it falls over.
How do I recognize diseases on a tree trunk?
Diseases of a tree trunk can be caused by fungi, bacteria or pests. Pay attention to warning signs such as nesting birds, bleeding injuries, splitting bark, drilling and feeding holes, rotting areas, fungal growth and dead wood in order to recognize a sick tree in good time and intervene.
Warning signs of a sick tree trunk
Now a layman cannot necessarily recognize a sick tree at first glance. Therefore, develop an eye for certain changes that indicate disease or pest infestation. These include, for example:
- Birds nesting in tree holes (especially woodpeckers, they prefer to look for rotten trees)
- bats living in tree holes
- bleeding injuries to the tree trunk, rubber flow, sap leakage
- damaged, cracking bark
- Drilling and eating holes in wood
- rotting spots, cracks
- visible fungal growth
- fungi growing out of the trunk or root area
- Deadwood
The latter is often an indication of problems that lie below the earth's surface, namely with the roots. If these can no longer adequately supply the tree, its above-ground parts will gradually die. There are a number of possible causes for this, for example an infection with viruses, bacteria or fungi. Voles can also cause considerable damage.
Typical diseases of the tree trunk
The symptoms mentioned above often indicate one or more of the following diseases. Many diseases are typical of the species, so their specific manifestation and cause depend on the respective tree species.
Wood Destroying Mushrooms
There are some types of fungi that destroy the wood from the inside - and cause the tree to rot, even though there is no sign of it on the outside. An alarm signal is often the fruiting bodies that suddenly grow near the trunk or from the trunk itself. By then, however, the infection is already well advanced because the actual fungus - the mycelium - is located in the wood of the trunk and / or in the roots.
White or brown rot
The wood-degrading fungi also include around 50 species that feed primarily on dead wood and cause either white or brown rot. You can recognize white rot by the fibrous wood, which often appears to be covered with a white-gray layer. With brown or soft rot, the wood turns dark brown to black.
Tree crab
The so-called tree cancer is caused by bacteria or fungi and is characterized by strong growths on branches, twigs and also on the trunk. In particular, growths that occur on the trunk (which are the overflowing of a wound with wound tissue) can become problematic because the supply to the tree can be disrupted or even interrupted.
Tip
Fruit trees in particular should be limed in autumn to prevent some of the diseases mentioned and pest infestation.