The tissue may be raised or sunken, discolored or split open. Twig cankers on junipers and leaf and stem blight of pachysandra are common examples. Most of the canker diseases are not controllable with fungicides. Maintaining plant vigor, protecting from injury, removing diseased parts and growing plants suitable for the site help prevent canker problems. The fungus invades the vascular system of the plant and clogs it, stopping the flow of water and nutrients.
Verticillium wilt is common on trees, shrubs, vegetables and fruits.
Discoloration of the vascular tissue sometimes can be seen when you cut diagonally through a branch. There are no effective chemical controls for wilts. Growing resistant species, maintaining plant vigor and sanitation provide the only controls. Smut fungi produce large amounts of black sooty spores which show up as unsightly dark brown or black blotches on leaves, stems and fruit. Corn smut is the common example in Ohio.