Weed control in lawns is always a hot topic and inspires many questions. This is a good time to control winter weeds that are now green in a Bermuda grass lawn.
You can spray the henbit, chickweed or other winter weeds with glyphosate, the active ingredient in Round-Up, as it will kill all green weeds (and plants) it hits. It will not damage your Bermuda grass, which is still dormant and brown and will not be affected by the glyphosate contact herbicide at this time of year.
Do not apply glyphosate to fescue lawns or any green plants you want to keep. You can use 20 percent horticultural vinegar (acetic acid) as an organic alternative control to dehydrate the green weeds.
This is also the season to apply pre-emergence weed killers to kill crabgrass and other summer weeds before they germinate. Think of liquid or granular pre-emergent herbicides as birth-control for weeds. They are best when applied when the yellow forsythia shrubs start to bloom but before the weed seeds germinate. Pre-emergents will kill from 75 to 95 percent of most weeds before they ever sprout to compete with your lawn.
Most folks use a weed-and-feed product that will apply the pre-emergent weed killer along with the first round of lawn fertilizer for the season. You can also buy most pre-emergent weed killers in liquid formulations, without fertilizer, to spray on your lawn just as many of the lawn treatment services would do if you hired this service.
Look for these active ingredients in your pre-emergent in most of the major brands: Balan, Treflan, Team, Gallery, sulfentrazone or my favorites: prodiamine (Barricade) and Dimension.