The Losing Battle Against Bermuda Grass

By Dennis Hinkamp

In the Midwest and South, Bermuda grass was thought to be the perfect lawn, it needed little water and because it grew close to the ground it required little cutting. For most Westerners, though, it is considered an invading weed.

"One of the more common questions I'm asked is how to control Bermuda grass in the lawn. My standard reply is 'asphalt'," says Jerry Goodspeed, Utah State University Extension horticulturist. Unfortunately, Bermuda grass can grow through asphalt and really thrive.

"Bermuda grass is a warm season grass planted for lawns in the south. Warm season grasses thrive in the heat when cool season grasses tend to go dormant or brown out. These grasses are not recommended for northern areas because they require hot temperatures to look green and attractive. In our Northern area, warm season grasses look brown and unattractive most of the year, only greening up during the extreme heat in June, July, and August," Goodspeed explains.

On the other hand, he says, cool season grasses such as bluegrass, fescue, and rye look green and lush from March through November. They relish in our cool climate and are recommended for most lawns in our area. Bermuda grass out competes all cool season grasses during hot summer weather, but during spring and fall it will sit dormant or grow very little.

One of the obstacles in the war against Bermuda grass is that it reproduces by seed, rhizome and stolons, Goodspeed says. The seeds are small and can move through watering systems. The stolons are above-ground stems that creep along the surface looking for new places to root, then start a new batch of plants. As they creep along the surface they shade and crowd out other grasses, forming a tough dense mat. It is not a pretty sight.

"The rhizomes are underground stems (that look like roots) that bury themselves up to two feet into the soil. If broken or chopped they form new plants. This makes hand pulling almost impossible because pieces left in the soil begin new growth starting the process all over again."

Bermuda grass control requires completely killing the whole plant--roots and all, he says. This means the plant must be growing and as healthy as possible at the time, which is usually during July and August. Unfortunately, eliminating Bermuda grass also requires killing the desirable cool season grasses it has invaded.

"No product will selectively remove Bermuda grass out of other grasses," Goodspeed emphasizes.

What does this mean to the homeowner ready to wage war on Bermuda grass?

Wait for the weather to get warm and the Bermuda grass to get fat, healthy, and sassy, Goodspeed says. This happens about the end of July through early August. Apply the first application of a non-selective herbicide such as glyphosate (sold under such names as Round-up, Knockout, or Kleen-up). This normally kills all the cool season grasses and makes the Bermuda grass good and mad.

Next, water, fertilize, and spend the next two weeks trying to get the Bermuda grass happy and healthy again. Then, launch a surprise attack on it one morning and apply another dose of glyphosate.

Repeat the process a third time, he says, trying to keep the Bermuda grass healthy and strong. Then hit it a final time with the herbicide. This third application will hopefully kill the tough plants that survived the first two applications.

By the end of August or first of September, most of the grass should be dead. Now is the time to re-work the soil and replant the area with an appropriate cool season grass blend. One slight problem with this "theory" becomes evident when the neighbors do not control their patch of Bermuda grass. It only takes a year or two before it has moved back into your yard.

For more information, contact your local USU County Extension office.
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Issued in furtherance of Cooperative Extension work, Acts of May 9 and June 30, 1914, in cooperation with the U.S. Department of Agriculture, Robert L. Gilliland, Vice-President and Director, Cooperative Extension Service, Utah State University, Logan, Utah. (EP/09-98/DF)