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Saturday - July 05, 2008

From: Cibolo, TX
Region: Southwest
Topic: Non-Natives, Diseases and Disorders, Grasses or Grass-like
Title: Brown spots in St. Augustine grass
Answered by: Nan Hampton

QUESTION:

Mr. Smarty Plants, My husband and I are in the Air Force and were recently moved to Cibolo Texas. We built a home and hired a landscaper to finish the yard May 07 (with irrigation system). We laid down St. Augustine grass in the backyard. We left to visit family on the east coast and when we returned we saw large brown spots of dead tan colored grass, with other patchs of rust brown. I believe it is a fungus- Anthracnose. But when I research what to do, I find nothing on it. We have heard that cornmeal will treat it from a friend of a friend. We aren't sure if that is true or a wive's tale. Needless to say, we are very worried that our expensive grass will continue to die. Any information or direction you could provide us would be very appreciated.

ANSWER:

First of all, let me refer you to two different sites that give you information on determining what your lawn problem is—Earth-wise Guide to Lawn Problems from the City of Austin and Texas A&M's St. Augustine Grass Diseaese Index. Certainly, anthracnose (caused by the fungus, Colletotrichum graminicolais) is one possibility and another is brown patch (caused by the fungus, Rhizoctonia solani). Chinch bugs and grubs of the June beetle are other possible causes of St. Augustine problems. The two guides (above) to lawn turf problems offer descriptions and photos to help you determine what your problem is and suggestions for solving them including cultural practices as well as chemical solutions. Your friend was, no doubt, talking about corn meal gluten which is the new 'miracle' organic treatment for fungal diseases on plants, algae control in water, and weed control. According to the Dirt Doctor, Howard Garrett, you should use horticultural cornmeal (or corn gluten meal) available at garden centers instead of cornmeal from the grocery store. Grocery store cornmeal is not as effective because it is mostly the starchy part of the corn kernel; whereas, corn meal gluten is the protein portion of the corn kernel. Garrett recommends applying the horticultural cornmeal at 10-20 lbs. per 1000 square feet to control fungal diseases in grass. It works by supplying nutrients to microorganisms that feed on the fungus. Here is more information about cornmeal as a fungicide. You can read the pros and cons of using cornmeal on Turfgrass Forums.