If a tree is not doing well, it can have different causes - from damage caused by frost to an infestation with animal pests and many others. Tree diseases, which are caused by an infection with microorganisms, pose a serious danger to the tree. While maintenance errors or pest infestation can still be easily addressed, an infection is very difficult to treat. For the right diagnosis, you need to be aware of the cause of the disease. First, you must find out whether it is a parasitic or non-parasitic tree disease. It should also be clarified whether there is an infectious disease or pest that needs immediate treatment. Nonparasitic Damage Include: Frost damage. Disorders in nutrient intake. Excessive Wetness. Environmental influences such as exhaust gases, road salt and acid rain Parasitic causes of damage. Other pests such as insects and their larvae (fresh wood and dry wood insects) Mushrooms Bacteria Virus Non-parasitic Causes of Damage The proportion of non...