Weather Fuels Growth Of Lawn Fungus
COLORADO SPRINGS – A fungus similar to the one threatening aspen trees in Colorado Springs, now is appearing on some lawns.
However, while the cytospora canker can kill trees, the ascochyta leaf blight merely turns lawns brown as they go dormant trying to resist the disease. A local lawn expert says both fungi thrive in weather extremes which can stress plants. Leaf blight also appears in newly-sodded lawns, or in established lawns after a dry spell.
Jon Rick of Integrated Lawn and Tree Care says the disease first shows up as a brown spot, but the initial response by property owners of increasing water and fertilizer is wrong. “The grass isn’t dead,” he explains. “By going dormant, it’s trying to protect itself.”
Rick says the best way to keep the fungus under control is to water less frequently and more thoroughly. “And when I say deep and infrequent, maybe three times a week maximum, even in these hot weeks. Water early in the morning before the wind starts blowing around, and you’re going to have sprinkler coverage issues.”
To avoid spreading the fungus, Rick also advises fertilizing less; keeping your mower blade sharp and cutting your grass no lower than three inches; avoid mowing wet grass; and bagging your clippings. Rick says most of the time, if you follow these steps, the fungus goes away by itself within a few weeks.
According to Rick, more than 90% of Colorado lawns use Kentucky bluegrass–a turf more suited to cooler temperatures–and thus is more susceptible to stress and leaf blight here. “A lot of people around here are kind of converting to fescue, which is a thicker-bladed type of grass. It’s a lot more drought-tolerant.”
Some experts recommend watering your lawn at least once a month in the winter so that it retains enough moisture and avoids dry spells.
