Cherry trees are common choices for growing in landscapes, and grow especially well in southern or central England. They belong to the same family as prunes and plums, and feature a red-brown bark and glossy green foliage. The trees range in size from 1.8 to 9.1 m (6 to 30 feet), and once established require little care from the grower. Though generally a hardy variety, cherry trees are susceptible to a number of diseases, each with specific tell-tale signs to look out for.
In the event of illness, leaves will often be the first part of the plant to exhibit trouble. Discolouration -- primarily yellowing or browning -- is indicative of a number of diseases. Most nutrient deficiencies, particularly iron or nitrogen, will cause leaves to turn yellow or brown, as will over watering, blights, fungal infections and a few pests. Additionally, certain types of mould will leave a sooty residue that resembles dust, which may create a faded or grey appearance of the leaves. Cherry trees require well-drained, nutrient-rich soil to stay healthy. If nutrients are lacking, a thorough mix-in of well-decomposed organic compost will aid in correcting the problem and improve water drainage. Other diseases, particularly fungal or bacterial infections, will require doses of fungicide, and usually pruning of infected areas.
Blight is caused by a fungus, and is a fairly common problem for cherry trees. Depending on the species of fungus, and the severity of infection, damage may be as minimal as temporary leaf discolouration to death. Symptoms most often associated with blight include a sudden wilting and premature drop of leaves, which may spread to twigs and branches. Flowers and fruit may also become discoloured and die. Reducing the amount of nitrogen-rich fertiliser will aid in controlling most types of blight. Additionally, a good dose of fungicide and proper pruning will kill the disease and prevent its spread to other trees.
A canker is a basic term for a dead spot along a branch or trunk of a tree. These areas may be found on any woody part of the tree and usually appear sunken, cracked or raised, depending on the type of fungus responsible. Most often, these fungi will grow between the bark and underlying wood, and the canker will be the first visual symptom, and may be part of a larger illness. Growers may also notice the cankers oozing fluid, another sign of infection. Depending on the source, a fungicide will be needed to fight canker problems. This should be done as soon as possible to prevent severe damage to the tree. All affected parts of the tree should be removed and destroyed.
There are a few mould and mildew problems associated with cherry trees, and these problems are often more prominent during times of excessive rain. Downy mildew grows to be a white or purple colour with a furry appearance. It is most prevalent on the bottoms of leaves and along stems. Downy mildew thrives in humid climates, and is best treated as soon as possible. This includes a dose of preventive fungicide, which should be applied during cool, damp weather. A second common type of mildew is powdery mildew, which appears as a white or grey colour and creates a powdery substance over the tops of leaves. Pruning and removing fallen debris may prevent infection, while a fungicide will help manage infection.