Willows are fast-growing but usually short-lived trees that grow naturally in wet areas. White willow, weeping willow, pussy willow and contorted willow are a few of the popular willows. The most damaging diseases are cankers, which causes twig branch and trunk die-back. Black canker and the same disease that causes canker in popular, Cytospora, are common in all areas. Willows brittle wood breaks easily in ice or wind.