Black walnuts in Boulder wiped out by fungus | VailDaily.com

Black walnuts in Boulder wiped out by fungus

BOULDER, Colorado – Nearly all black walnut trees in Boulder are being killed by a fungus, and city officials are telling residents they’ll have to cut down almost every one of them.

The walnut trees have been infested with a fungus that comes from bugs including walnut twig beetles. The city plans to start sending out notices Monday to owners of black walnut trees that they will likely have to remove diseased specimens.

City forest officials say there are about 250 to 300 black walnut trees in Boulder, nearly all of them carrying the fungus. A year ago, the city had almost 400 dead or dying walnut trees. Sick trees were removed, but the fungus continued to spread.