Lawn Diseases: Brown Patch

Lawn Diseases: BROWN PATCH

So What Exactly is Brown Patch Disease?

Large brown patch lawn disease can seriously affect the beauty of your lawn. These patches appear because of various strains of the fungus Rhizoctonia solani. During hot weather, they can emerge and destroy areas your yard overnight. Particularly in the southeastern United States, this condition can infect many types of both warm-season and cool-season lawn grasses. And unfortunately, it is one of the most damaging of all turf diseases. The problem is that many homeowners have no idea how to identify the disease, let alone how to fight it. So let’s take a look at how to identify brown patch, where it comes from, and how you can remedy it.

How Can I Spot It?

Typically, the disease will cause large and brown circular shapes of thinned-out grass. Sometimes the grass may die off and create dead spots. In other cases, the center of the patch will recover, resulting in a donut-like shape on your lawn. Keep in mind, however, that areas damaged by brown patch are not always circular. Sometimes they may also grow together and be extremely irregular in shape. Look for what appears to be a dark, smoky ring around the patches of dead grass. Infected grasses often appear perfectly healthy until they become matted-down, are infected, and start to die.

What Causes It?

Brown patch disease most often occurs in very hot, humid conditions. It is therefore very common in the southeast. Look for it when temperatures are over 85 degrees Fahrenheit in the daytime, and do not fall below 75 degrees at night. If you’ve been using lawn fertilizers with very high levels of quick-releasing nitrogen, you’ll be more likely to have the disease. So be sure to avoid these kinds of fertilizers during hot and humid weather.

What Can I Do About It?

The most effective solution for brown patch disease is prevention in the first place. Follow generally accepted lawn care principles (mowing to the right height, giving 1 inch of water per week) and be sure to do your watering early in the day. Avoid excess nitrogen from overfertilization and aerate your soil regularly. When it comes to treating the disease itself, fungicide may be necessary, in which case you’ll want to contact a professional.

-- Philip

Image credit: Garden Supply Company