Is your willow tree looking a bit worse for wear? There are two diseases that are common in willow trees in North America: willow scab and black canker disease. The two cause similar symptoms, but it is usually possible to tell the difference if you examine the tree closely.
Black Canker of Willow
Many trees are susceptible to various canker diseases, but the strain of fungus that causes black canker disease in willows only infects various species of willows – not other tree varieties.