Fall Lawn Diseases
November 19, 2019
While hot summer temperatures can often stretch far into fall, the moment things cool down you may see lawn diseases crop up quick. Rising humidity, extra rainfall, and potential over watering with irrigation systems create the perfect conditions for certain lawn diseases, such as Brown Patch and Take All Root Rot.
Brown Patch Disease
Brown patch is caused by the fungus Rhizoctonia solani. The fungus thrives in the fall and spring with cool temperatures and high humidity. Brown patch affects many types of lawngrasses including St. Augustine and Zoysia. If you plant a winter lawn of perennial rye, brown patch can be an issue.
Over watering with your irrigation system, when conditions are already humid or rainy, is one of the biggest boosters of brown patch disease. Brown patch is also commonly spread from lawn to lawn by lawn equipment.
Watch for these brown patch symptoms in your lawn:
- yellow circular patches that range from a few inches to a couple feet in diameter
- patches that turn from yellow to tan & brown
- tan lesions on grass leaf blades that have a dark brown border
- in extremely wet conditions, grey, cotton-like growth is seen on grass blades
Brown patch is rarely a death sentence for your lawn, unless your lawn is already stressed from other factors. Therefore, it’s important to keep your lawn properly maintained by means of aeration and fertilization as well as implementing proper mowing heights. In addition, make sure to decrease water usage in the fall. There are low-impact fungicides that can be applied to treat brown patch.
Take-All Root Rot
Take-All Root Rot (TARR) is a serious disease that can kill your entire lawn. The disease, caused by the fungus Gaeumannomyces graminis var. graminis, attacks St. Augustine, Bermudagrass, Zoysiagrass and Centipedegrass lawns and cool season grasses such as fescue & rye. Bermuda grass is not as susceptible.
The ideal conditions for the spread of TARR include high humidity and temperatures in the 60s, which occur in the fall & spring. Like brown patch, proper maintenance practices can help ward off the disease. Unfortunately, TARR can be spread from lawn to lawn by lawn equipment.
Symptoms of TARR include:
- Irregular shaped patches of yellowing grass several feet across
- Yellowing patches that fade to brown
- Brown dying roots
We have had success with treatment for TARR with our SEASONS lawn program coupled with additional treatments, although it can be a lengthy process or require complete lawn renovation.
If you suspect you may have a lawn disease spreading through your landscape, contact our lawn healthcare specialist for help.