Bermuda grass (Cynodon dactylon) is a warm-season grass known for its hardy nature and drought tolerance. Originally from southeast Africa, it generally grows in U.S. Department of Agriculture plant hardiness zones 7 through 10. Occasionally, moss may start growing in your Bermuda grass lawn. While various herbicides can cure this problem, changing how you care for your Bermuda turf can stop this invader in its tracks.
Decrease Watering Frequency
Moss thrives in constantly moist conditions. By reducing watering as much as possible, you help to dry out the soil and kill the moss. An added bonus, decreased watering frequency paired with deep watering encourages Bermuda grass to grow deeper, healthier roots, which in turn improves lawn vigor, health and appearance. For the best results with Bermuda grass, apply enough water to moisten the soil to a depth of approximately 6 inches -- this is the depth where 80 percent of Bermuda grass roots lie. Then, hold off on watering until the grass shows slight signs of drought stress, such as slight folding of the grass leaves.
Increase Light and Air Circulation
Humid, still air encourages moss growth. By enhancing the penetration of sunlight and increasing air circulation over the surface of your lawn, you create anti-moss conditions that stop and kill the spread of this pest. Cut back any tree branches that are hanging over your lawn, thin out nearby stands of bushes and hedges, and rearrange lawn furniture to expose more of the lawn to sun and air.
Regular, frequent mowing of your Bermuda grass lawn helps to prevent and control moss. For example, it increases sunlight penetration to the soil surface by reducing the shade created by tall grass. It also improves grass vigor, which helps the grass compete and push out the moss invasion. For the best results, maintain a lawn height of approximately 1 inch. If your current Bermuda grass height is significantly higher than this, don't cut it all at once. A maximum of 40 percent of the grass height can be removed in a single mowing. More than this causes significant stress to Bermuda grass.
Aerate the Lawn
Rent a core lawn aerator from a garden store or nursery and aerate your lawn. This helps loosen the soil under your lawn, reducing the soil compaction which encourages moss. It also helps to break up the moss mats and algae crusts in your lawn and dry out the moss surface, killing it in the process.
Apply Copper Sulfate
Treat your lawn with copper sulfate if all other methods of moss control fail to rein in this pest. Mix 3 ounces of copper sulfate with 3 gallons of water for every 1,000 square feet of lawn surface. Pour the mixture into a sprayer, such as the type used to apply liquid fertilizer, and spray it on your lawn to kill the moss while leaving your Bermuda grass intact.
- University of Missouri Extension: Bermudagrass
- U.S. Department of Agriculture Natural Resources Conservation Service: Bermudagrass
- Alabama Cooperative Extension System: Moss and Algae Control in Lawns
- Texas A&M AgriLife Extension: Bermudagrass
- University of Georgia Extension: Controlling Moss and Algae in Turf
- University of Maryland Extension: Moss Control in Home Lawns
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