A website from UGA Cooperative Extension

County Agents receive hundreds of calls about all of the weeds that decide to “pop up” and start flowering in spring.  Well now is the time to do something about it.  The weeds that we see flowering in lawns in the early spring are what we refer to as winter annuals.  This means that they germinate in the fall, grow throughout the winter and flower and die in spring. 

Once your lawn has a purple shade to it form the henbit flowers it is too late.  Although we have some really good herbicides timing of application is critical for good control without repeated, and costly applications.  Ask any farmer around here with a pigweed problem.  They will tell you that, “Timing is everything”!

Applying a herbicide in the fall will help reduce or eliminate your need to do anything in the spring.  There are several products that we can employ in this type of weed control strategy.  For centipede and st. augustine we can use atrazine in the fall to control many of our problem weeds.  The cautions for atrazine use are to not over apply and not apply during spring greenup.  For those with bermudagrass atrazine can be used once the grass has gone dormant. 

For those of you with either bermudagrass or zoysia you have some options as well.  Products with active ingredients such as pendimethalin, oryzalin, and benefin are good products that will control annual bluegrass, chickweed and henbit.  Dithiopyr, which is in Turf & Ornamental Weed & Grass Stopper, controls a few more weed species, but might be harder to find.  For longer control a 2nd application may be necessary.

I know how things go though, you get busy with fall and the holidays and next thing you know it’s January.  By then all of these weeds are up and growing, but doing so inconspicuously.  It is not too late to do something about it.  You can go with a 3-way herbicide mix and kill almost any broadleaf weed in the lawn.  There are so many 3-way mixes I am not going to start and name them.  The only thing you need to be careful with is winter annuals, St. Augustine, and centipede.  Auxin herbicides like 2, 4-D and dicamba can injure these plants and grasses so care must be taken.  Use low pressure when you are near winter annual flowers and lower rates on sensitive grasses. 

I hope this helps you better prepare to deal with winter annual weeds and results in more time in the spring to get your pool clean and your garden planted.  For those of you that have called about lawn burweed the last couple of years now is the time to start working on getting that weed under control as well.  Burweed, along with other winter annuals have already germinated so using both a pre- and post-emerge herbicide will be needed to provide a weed-free lawn into the spring.

Contact your County Agent for more information Here

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