Although Bermuda grass (Cynodon dactylon) is tough, without proper maintenance, it is susceptible to foxtail (Setaria spp.) infestation. The summer annual weed germinates from seed in the spring and competes with Bermuda grass for light, water and nutrients. Usually, a foxtail infestation indicates that the Bermuda grass requires a change in growing conditions. Most Bermuda grass varieties thrive in U.S. Department of Agriculture plant hardiness zones 7 through 10, but a few grow in USDA zones 5 and 6. Bermuda grass prefers well-drained, nitrogen-rich soil and full sun. The best way to control foxtail in Bermuda grass is maintaining a healthy, dense lawn and applying herbicides.
Things You'll Need
- Pre-emergent herbicide containing benefin, dithiopyr or oryzalin
- Post-emergent herbicide containing 2,4-D, mecoprop, dicamba, clopyralid, triclopyr or fluroxypyr
Mow Bermuda grass to a height of 1 to 1 1/2 inches when it is dry. Mowing to the highest length possible creates a shaded environment that helps prevent seed germination and promotes Bermuda grass health. Clean the mower to prevent spreading seed to non-infested areas. Change the mowing pattern each time, but never remove more than one-third of the plant at one time.
Provide 1 to 1 1/2 inches of water per week -- about 635 to 940 gallons of water per 1,000 square feet. Moisten the soil to a depth of 6 inches each watering. Irrigation will help control foxtail by improving Bermuda grass health.
Apply 1/2 to 1 pound of nitrogen per 1,000 square feet a few weeks after Bermuda grass starts turning green. Fertilizing will help control foxtail by improving Bermuda grass health.
Treat infested areas with a pre-emergent herbicide containing the active ingredient benefin, dithiopyr or oryzalin. Herbicides vary, so read the label instructions for the correct strength, timing and method of application. On average, the best time to apply a pre-emergent herbicide is two weeks before seed germination. Pre-emergent herbicide will usually make post-emergent herbicides unnecessary.
Apply a post-emergent herbicide containing the active ingredient 2,4-D, mecoprop, dicamba, clopyralid, triclopyr or fluroxypyr to infested areas. Herbicides vary, so read the label instructions for the correct strength, timing and method of application. Most herbicides should be applied within 30 days after foxtail emerges. For better control of foxtail, combine a herbicide containing the active ingredient MSMA with a herbicide containing 2,4-D.
Tips & Warnings
- Removing layers of thatch thicker than 1/2 inch will help improve the effectiveness of pre-emergent herbicides.
- Bermuda grass is considered moderately invasive. If allowed to creep beyond the lawn, it can interfere with the health of other plants.
- MSMA may cause minor damage to Bermuda grass.
- Wear gloves, eye protection, a long sleeve shirt, pants, socks and chemical-resistant when handling herbicides. Keep animals and children away from herbicides. If skin comes in contact with herbicides, wash it with soap and water immediately.
- The University of Tennessee Extension: Bermudagrass Athletic Field Management Calendar
- Colorado State University Extension: Control of Annual Grassy Weeds in Lawns
- North Carolina State University: Bermudagrass
- Virginia Cooperative Extension: Weeds
- USDA Natural Resources Conservation Service: Bermudagrass