Winter best time to kill weeds
Spray herbicides now while turf is dormant.
By Sharon Omahen

Lawn care tends to be the last thing on homeowners' minds during the winter. But a University of Georgia expert says this is actually the best time to rid your lawn of pesky weeds.

UGA weed scientist Tim Murphy has been helping homeowners and professionals kill weeds in Southern turf grasses for more than 20 years.

"It's easy to forget about your home lawn when you're not having to mow every week," Murphy said. "Homeowners should know that from now until mid-March is the ideal time to spray your lawn for our winter spectrum of weeds."

Weeds still growing

Even though the warm-season turfgrass in your lawn isn't green, various winter annual weeds are growing. These include common chickweed, henbit and annual bluegrass.

"These weeds grow slowly at cool temperatures," he said. "But in just a few weeks they will grow profusely as temperatures rise in the spring."

Controlling these weeds is much easier now when they are small than when the rapid growth spurt hits in spring, he said.

Murphy recommends using a postemergence herbicide to control the various winter weeds in your lawn. Select a day when the air temperature reaches 50 to 60 degrees Fahrenheit and apply a "selective" herbicide.

"Selective herbicides control some species without affecting others," he said. "Determine whether your weeds are primarily broadleafs or grasses and then select the proper herbicide product."

Know what you're fighting

Grass weeds have long leaves with parallel veins, while broadleaf weeds have netted veins and, as you would suspect, broad leaves.

"Broadleaf weeds are also the ones that typically produce colorful flowers," he said.

Applying postemergence herbicides can slightly delay the onset of spring green-up in turf grasses, Murphy said. But the grass will recover in about two weeks.

"Having thick, dense mats of winter annual weeds can be more detrimental to spring growth than the temporary injury associated with the herbicide applications," he said.

The way to avoid delays in green-up is to treat these weeds before warm-season turf grasses begin their spring green-up process, he said.

Using preemergence herbicides in early September, he said, followed by postemergence herbicides in the winter is a good strategy for future years, especially on sites where overseeding isn't planned.

Call, log on for more

Many herbicides are available for use on home lawns. Your county UGA Cooperative Extension agent can advise you on the appropriate product, when to apply it and the expected results. Just call 1-800-ASK-UGA1.

For more research-based turfgrass recommendations from UGA, visit www.georgiaturf.com.