Bermuda grass (Cynodon spp.) is found in more than 100 countries as a warm-season turf and forage crop. The Texas Cooperative Extension lists bermuda grass cultivation ranging from New Jersey and Maryland southward to Florida and west through Texas and Kansas. Proper selection and application of herbicides protect bermuda grass from damage.
Weeds are considered serious pests in bermuda grass. While proper management helps control weeds, often environmental stress or lapses in management invite a rapid weed invasion. Broadleaf weeds found in bermuda include chickweed, dandelion, clover, dichondra and henbit. Grassy weeds such as crabgrass, dallis grass, bahia grass and blue grass are also common problems, states the Texas Cooperative Extension.
Herbicides safe for use on bermuda lawns are selective, targeting only certain plants. Weeds compete with bermuda for soil nutrients, water and space, leaving the bermuda susceptible to increased weed invasion and pest problems. Weeds grow quickly and propagate easily, tending to completely take over a bermuda pasture or turf.
Types of Weed Control
There are two types of selective weed control for application on bermuda grass. Pre-emergent herbicides target the seeds in soil. Usually incorporated into the soil after application through plowing or irrigation, the pre-emergents stop the germination of the weed seeds.
Post-emergent selective herbicides kill plants after they start growing. Application usually occurs when weeds are between 2 and 4 inches tall or in the fall when plants are storing nutrients. This type of herbicide interrupts various chemical processes such as photosynthesis, root growth and protein production.
Not all herbicides are safe for killing weeds in bermuda lawns. Safer herbicides for established bermuda application include metsulfuron, 2,4-D, MCPP, dicamba and MSMA. Herbicides safe on bermuda grass at seeding include foramsulfuron, rimsulfuron, trifloxysulfuron and sulfosulfuron.
Follow all manufacturers' label directions when applying herbicides to bermuda. Applying herbicides at a rate greater than the suggested application rate may result in damage to the turf. Most sprays require application on days that are under 85 degrees with little wind and no forecast of rain. The Garden Counselor, an informational website on lawn care, recommends applying weedkillers to mature lawns and waiting four to five months before application on newly planted grass.