Apple Scab is caused by a fungus that can be identified by black or brown lesions that appear on the leaves or fruits of the tree.
Cedar Apple Rust causes colored spots on the leaves in the spring. In the summer, the spots turn into cone-like structures.
Cytospora Canker can be identified by a canker in the bark and a browning or dying of the tree's needles. Cytospora Canker is highly destructive and often fatal.
Fire Blight is a highly contagious disease. The name refers to the blackened appearance of the leaves of a plant infected with Fire Blight.
Oak Wilt is capable of rapidly killing an oak tree. Prevention and control of the spread are key when dealing with this disease.
Physiological Leaf Spot of Tulip is a fungus disease that causes black spots to appear on the leaves of tulip trees.
Rhizosphaera affects spruce trees. The disease kills the older, inner needles first. The infected needles turn brown before falling off.
Sycamore Anthracnose is a fungus disease that causes odd, unsightly growth patterns in the tree and an early loss of leaves.
Tar Spot of Maple is an unsightly black spot on the leaves of a maple tree. It is completely harmless.