Black Knot Disease

dutch-elm
dutch elm beetle

Dutch elm disease (DED) causes wilt and death in the American Elm tree. The disease is caused by the invasive fungal pathogen, Ophiostoma novo-ulmi, which is transmitted by elm bark beetles. The beetles spread the DED fungus when feeding. The DED fungus can also spread from tree to tree through root grafts. Once a tree is infected with DED, the tree will show signs pretty quickly, within 4-6 weeks. These symptoms usually consist of yellowing or wilting of leaves on a normally healthy looking tree. Unfortunately, by the time this happens, the interior of the tree has suffered. Although there are treatments that can prolong a trees life, depending on the state of infection, there are no known cures for DED and the infected tree will eventually die. To help prevent spread of DED, never transport elm wood with bark to different locations.

Call Now Button