Every year during late February to mid April, I get those predictable homeowners that bring in bags of winter annual weeds from their lawns wanting advice on how to control them. They usually seem a little put off, disappointed and confused when I tell them that it’s too late to bother with controlling winter annual weeds now (late winter to early spring). Standing there holding a bag of weeds and with a lawn full of weeds back at home and not satisfied with my comment, they follow with a statement and a question such as, “Well, my lawn is full of these weeds now. What can I do?” I tell them to just mow them and as we move into warmer weather toward the latter part of April and into May these weeds will die off.
At this point, looking a little frustrated, they may ask, “Is there something I can spray on my lawn to kill these weeds?” To which I reply, “Yes, but it’s pretty much a waste of time and money this late into these weeds lifecycle.” I then try to explain that these particular weeds are winter annuals. By now, they’ve produced most if not all of their seeds. So you now have a yard full of weed seeds that will lie dormant through the summer awaiting the arrival of fall or early winter to sprout to begin the cycle again. If you’ve had a history of winter annual weeds in your lawn, the best option is to apply a preemergence herbicide during the month of October. This will be just before the winter annual seedlings germinate and emerge. That way, you are breaking the cycle. And that’s the way to win the battle with the winter annual weeds. It may be helpful to put this job on your calendar. If you don’t, October may come and go and the opportunity will be missed.
If you’ve had a history of problems with winter annual weeds, a second application may be required six to nine weeks after the initial application to achieve season-long control. Always follow the label directions and precautions when using any pesticide, including herbicides.
Some of the more common winter annual weeds are chickweed, henbit, Carolina geranium, annual bluegrass, hop clover and lawn burweed.
If it’s a small infestation, perhaps hand removal is the easiest and cheapest way to control them. If you need to use a herbicide, choose one that is safe for the kind of grass you have and effective on the weeds you have.
Larry Williams, UF/IFAS Extension Agent, Okaloosa County, October 18, 2013