Mountain Ash Disorder: Fire Blight
Author(s) M.F. Heimann, G.L. Worf.
Fire blight sometimes causes dramatic and serious damage, blackening leaves and either the vegetative shoots or blossoms of affected branches. While it does not affect a large number of mountain ash trees in Wisconsin, other common hosts include varieties of apple and flowering crab, cotoneaster, and other members of the family Rosaceae.
Find out more about fire blight and how to control it with this handy fact sheet (2 pages; Revised in 1995).