Killing Bermudagrass
by Bob Chapman
Bermudagrass has been called devil-grass, wiregrass or dogs-tooth grass. I've called it many worse names over the years. Bermudagrass is a perennial grass, spreading by underground rhizomes, above ground stolons and by seed carried in by wind, lawn mowers, clothing and shoes. It is found in areas where the ground does not freeze. There are strains developed that make fine lawns but the common Bermudagrass can become a serious pest, invading lawns, flowerbeds and shrubbery borders. Bermudagrass goes dormant in the winter when the temperature drops below 50 degrees, even in frost-free climates, the stems turning yellowish-brown and looking very unsightly.
If you are not sure if you have Bermudagrass or crabgrass see the descriptions and illustrations at the end of the article
Bermudagrass must have sunshine to grow, so it is usually not invasive in densely shaded areas.
Killing Bermudagrass in open areas can be accomplished with glyphosate, a broad-spectrum systemic herbicide, sold as Easy Gone Weed and Grass Killer or Roundup. You'll need to use precautions in application, as this herbicide can kill most vegetation contacted. Glyphosate will kill Bermudagrass only when it is in an active, growing state, not when it is dormant. Applications are done from spring to fall, when the leaves are fully developed and green.
Glyphosate is a systemic herbicide, killing even the furthermost roots. It kills by blocking the synthesis of a protein found only in plants. Visual effects, such as graying and browning, will appear 7-10 days after treatment. Systemics are adsorbed onto soil particles and microbially degrade to carbon dioxide, nitrogen, water and phosphate, common natural components of the environment.
CONTROLLING BERMUDAGRASS IN LAWNS
Bermudagrass will invade even the best of well-kept bluegrass, fescue or ryegrass lawns. The exception is that Bermudagrass does not thrive in shade. Bermudagrass can be controlled in existing lawns by spraying it three times at three-week intervals during the growing season (usually May-July, before it goes to seed) with Turflon ester. If not available locally, Turflon ester can be ordered online from www.montereylawngarden.com. Unless the weed is widespread, spot treatment in late spring and summer with a systemic herbicide is suggested, followed by reseeding. To renovate an entire Bermudagrass-infested lawn, spray it with glyphosate (Easy Gone Weed and Grass Killer or Roundup), wait a week, spray the spots missed and wait one more week before removing or turning under.
ERADICATING BERMUDAGRASS IN FLOWER BEDS
Spot spraying with glyphosate can be done if protection is provided to prevent spray drift from contacting desirable vegetation.
-One way to do this is to have a helper hold a piece of cardboard or thin plywood between the targeted Bermudagrass and your prized plants. If using a pressure tank sprayer, refrain from pumping it up very high to lesson the chances of creating a fine mist that can drift, unnoticed, contacting other plants.
-You can cut off the top and bottom of a plastic or cardboard 1/2-gallon milk container or large soda bottle and place this over the clump of Bermudagrass. The spray will be prevented from contacting nearby plants.
-If space allows, use a small paint roller and pan, putting the solution of glyphosate in the pan and rolling the moistened roller over the offending Bermudagrass, ensuring that no contact is made with leaves and stems of your flowers.
CONTROLLING BERMUDAGRASS IN SHRUBBERY BORDERS
Use a tank-type pressure sprayer in larger areas, a ready-to-use sprayer in isolated spots. Caution: Do not allow the spray or spray drift to contact the greenish bark of trees or shrubs. Evidence exists that glyphosate is absorbed through the bark of these trees and shrubs, causing growth defects. Use the shield method described above to prevent mishaps. Ortho Grass-B-Gon Grass Killer (Fluazifop-butyl) can be applied over the top of broadleaf ornamentals without injury.
CONTROLLING BERMUDAGRASS IN JUNIPERS
Grass-Getter, a post-emergent grass killer will control Bermudagrass. Follow directions on the label for amounts, timing and methods of application. Repeat applications may be necessary.
KILLING BERMUDAGRASS IN OPEN AREAS
Use a tank-type pressure sprayer, keeping the pressure high, creating a fine spray that will cover a wide area. Remember that glyphosate kills most vegetation on contact. Keep it away from desirable plants.
DO YOU HAVE BERMUDAGRASS OR CRABGRASS?
BERMUDAGRASS
Many gardeners confuse the two. Bermudagrass is a perennial grass, pervasive in lawns, flowerbeds, waste areas and shrubbery borders. It loses most of its leaves in winter and the wiry stems turn a yucky yellowish-brown color in wintertime.
CRABGRASS, AN ANNUAL GRASS
Crabgrass is an annual weed, most commonly found in lawns or flowerbeds adjacent to lawns. It needs lots of water to survive. Yellowish-green, wide leaves emerge in the seedling stage in lawns, usually in early April-May. Crabgrass is easily controlled by spraying with a liquid crabgrass killer when the leaves are about 1" long. Repeat applications are needed for killing mature crabgrass.
In the fall, crabgrass dies, leaving a mass of dead, decaying matter that looks very unsightly in the lawn.
Prevent crabgrass by applying a pre-emergent herbicide. An easy way is to spread a fertilizer/weed preventer combination in the middle of February. The herbicide prevents seedlings from growing and they die before becoming unsightly.