Home Gardening

Brown patch fungus troublesome
The Coast Gardener Newspaper and Web Column - August 4, 2001

You may remember reading my story regarding take-all disease a few weeks ago. Unfortunately, I have confirmed several cases of this fungal disease in area lawns during the last couple of weeks. It is important to note, however, that grass can become unsightly and die for many reasons.

The cause of turfgrass damage is often difficult to determine if considerable time has lapsed between damage and diagnosis. Diseases and insects often get the blame when environmental stress and cultural practices are often the culprits. Nutrient deficiencies, soil compaction, tree competition and herbicide damage can all show symptoms that look similar to disease or insect damage. While these factors may not initially cause a disease or insect outbreak, added stress coupled with improper irrigation and mowing heights can result in future outbreaks.

Another fungal disease that visits manicured Coast lawns is brown patch. This is a common disease that is prevalent in St. Augustinegrass and centipedegrass each year. Thankfully, brown patch is easier to treat than take-all. Grass tends to recover faster as well.

This disease is characterized by the development of irregular, circular areas a few inches to several feet in diameter. These areas will usually appear as brownish to grayish patches. These water-soaked or scalded spots in the lawn spread rapidly, becoming large, brown areas. Generally, brown patch fungus attacks the base of leaf sheaths where they are joined to stolons (runners). Leaves turn yellow in St. Augustinegrass and a reddish color in centipedegrass. If left untreated, large areas of turfgrass can die.

There are several factors that tend to make grass more susceptible to brown patch. Excessive applications of nitrogen fertilizer promote a lush growth of grass that is readily attacked. Watering late in the evening or at night allows grass to remain wet for long periods of time. Wet conditions create a perfect environment for the fungus to flourish. Thatch is a buildup of partially decomposed leaves, stems and roots that promotes excessive disease development as well.

What can you do to keep brown patch out of your yard? Prevention is the best defense against this disease.

If proactive efforts are still not enough, a fungicide treatment will be necessary for effective control. Some products available include Heritage, Bayleton, Terraclor and Strike. Regardless of the fungicide you choose, carefully read and follow label directions. Make certain that the product is labeled for your particular turfgrass and is an approved fungicide for brown patch control.

Pay careful attention to your lawn care practices. When it comes to diseases like brown patch, they surely make a positive difference.

These archived gardening columns were written by Chance McDavid, former Harrison County Extension Agent.