Winter weed control 01-28-08

Now is the time to apply post-emerge herbicides that have activity on many winter weeds such as henbit, chickweed, clover, lawn burweed, wild garlic and wild onions. While our warm season lawns are still dormant and the weeds are actively growing, we can allow these weeds to get tall enough to get maximum herbicide coverage and absorption. Once mowing begins, there is less leaf surface on these weeds and they have by then matured into a reproductive stage making them much harder to control. There is also less danger of injury to the turf or adjacent landscape plants at this time. 

Image (imazaquin) is labeled for warm season turf species. It has very good activity on wild garlic and onions and can control many sedges that may also be present in the lawn. Hormonal herbicides such as 2,4-D, dicamba, MCPP has excellent activity on most annual broadleaf species and has fair activity on wild garlic and wild onions.

Products having the combinations of these active hormonal ingredients usually are more effective than one single chemical alone.  The latest chemistry class of herbicides, labeled for lawns that have good activity on many broadleaf species (including wild garlic at very low rates), are the sulfonylurea products (Manor, Blade, Corsair, Certainty, Monument, etc.). 

For specific use rates and timing always read the label of any pesticide before applying as not all products are labeled for residential turf or for all warm season turf species. 

Published January 28, 2008

Dr. Wayne Wells is an Extension Professor and Turfgrass Specialist. His mailing address is Department of Plant and Soil Sciences, Mail Stop 9555, Mississippi State, MS 39762. [email protected]