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Identifying Lawn Disease Problems

Lawn diseases can be aggravating and difficult to deal with at times. Not only are they hard to control in some instances, but they are hard to identify.

Three common disease problems we encounter in North Dakota lawns are:

1. Leaf spot and melting out;

2. Powdery mildew; and

3. Necrotic ring spot.

Leaf spot disease is present in trace amounts in every lawn, but can cause extensive damage--especially in spring. Lawns thin out badly when the disease moves into the crown or lower stem areas.

Powdery mildew often occurs in shady parts of the lawn, such as on the north side of homes and under trees. At first, infected leaves show a white powdery substance on the surface; later the leaves may become quite yellow or brown.

Necrotic ring spot has become a serious problem in recent years, particularly with "middle-aged" lawns of two to eight years. It is a warm weather disease and can appear any time from May through September. The most characteristic symptoms are perhaps the sudden onset of yellowing and the death of distinct circular patches or rings of grass. Affected spots are usually from 6-12 inches across. Often, the center of some of the spots remains alive and green. This creates a donut pattern.

For future reference, you may want to obtain a copy of Extension bulletin PP-950, "Lawn Diseases," which is available at your county office of the NDSU Extension Service.

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For More Information Contact your North Dakota County Extension Office of the NDSU Extension Service for additional information or see our main NDSU Web Page for publications and articles on Agriculture, Horticulture, Youth and Family, Business and Community and Food and Nutrition at  http://www.ag.ndsu.nodak.edu/