Even the best of lawns are subject to turf disease problems, especially during warm, humid, rainy periods such as often experience in late spring to early summer. Most turf diseases are more active when the temperatures are warm, with high humidity and excess moisture. As a homeowner, you see your grass every day, so you need to be on the lookout and watch for brown patches, yellowing areas, and thinning turf. Turf disease can move in quickly and wreck havoc on what normally would be a
beautiful green lawn.
Brown Patch is one common turf disease which affects Fescue, Zoysiagrass, St. Augustine, and Bluegrass lawns mainly. It can normally become a problem around early May and on into June, as temperatures and rainfall increase. It is characterized by yellow to brown patches, often in irregular circular patterns. The outer area of the diseased area may have a slight orange or yellow ring as it expands into healthy turf. It is caused by a fungus, which can infect healthy turf during times of warm temperatures and excess humidity and rainfall. Excessive nitrogen fertilization and excessive irrigation are two practices which can increase the severity of this disease.
Zoysiapatch is similar to brown patch, occuring during spring and fall. It affects Zoysiagrass only, and really needs to be treated with a fungicide as soon as symptoms appear. Pythium blight, powdery mildew, rust, and many other turf diseases can develop quickly under the right conditions, so be on the lookout for any sudden changes in the appearance of your turf.
Do not water in the evening if you have signs of Brown Patch, or any other turf disease. During rainy periods, supplemental irrigation can do more harm than good, by helping to spread turf disease. Keep your mower blade sharp, and don’t leave excess clippings on the turf after mowing. A turf fungicide should be applied as soon as symptoms of turf disease appear in most cases to prevent the further spread of the disease.
Spring Dead Spot is one of the most troubling diseases of bermudagrass lawns. It appears as circular dead areas in what otherwise is green, healthy turf. The fungus actually infects the turf in fall, and shows the symptoms the following spring as dead spots. As the summer progresses, the spots will fill in from the sides with bermudagrass.
The frustrating part of this disease is that there is not a good control for it. A homeowner can dig the spots up in the spring, even removing the top 3-4” of soil. Replace with fresh soil and a new piece of sod, and the spots will probably not be back in the same place. Otherwise, they will returnoften larger and more of them.
There are two turf fungicides that are labeled for control of Spring Dead Spot, “Eagle” and “Rubigan”, which we have applied on some lawns. We have found that the control is rather inconsistent, so it is not a definite cure for the disease. It needs to be applied during early to mid-fall, before the dead spots come out.
While the fall fungicide treatment does not completely cure the disease, it does appear to cut down on the number of dead spots, while helping to speed-up the rate at which they fill in with healthy grass the next spring. Proper cultural practices, such as core aeration and proper application of fertilizers, will help combat the disease.
Be on the lookout for these, and other turf diseases which may turn your beautiful green lawn into a brown wasteland. If conditions merit, a turf fungicide will need to be applied to stop the fungus disease in it’s tracks.