Canker is a fungal disease which affects woody plants (list below.) The leaves of an affected tree will wilt, turn brown and drop. Other indicators are sunken areas of bark, oval with dark center, at the base of affected twigs and branches. Spores are produced in the sunken areas during wet periods in the spring and summer. Wind and water spread the spores to other branches, and to other trees, where it enters through wounds in the bark. The fungus spreads in all directions, cutting off water and food to areas beyond the canker. If not detected early, a canker will kill the branches above the canker.

There is no chemical solution for canker. Affected trees must be pruned, and the removed wood destroyed to pervent further spread of the disease.

This is an example of the value of a professional inspection of trees on neighboring properties as a preventive measure.
Some Common Trees Susceptible to Canker
(Botryosphaeria ribis)
Apple Avocado Azalea Chestnut Citrus
Currant Dogwood Firethorn Fig Hickory
Holly Maple Pear Pecan Poplar
Redbud Rose Sweet gum Sour gum Willow