The first touch of cool weather always tells me to start thinking about pre-emergence weed control. 

I am sure that is what everyone else thinks about, right?  Spring time is full of calls concerning weed control in home lawns.  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 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 grass we can use atrazine in the fall to control most of our problem weeds.  The cautions for atrazine use are to not over apply and not apply during spring greenup.  For those with Bermuda grass atrazine can be used once it is dormant. 

For those of you with either Bermuda grass or zoysia you have some options as well.  All of those products that are advertised for crabgrass control can be used to control several winter annuals.  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 second 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.  We still have more than a couple of weeks of warm weather I am sure, but October should be a good month to apply some of these herbicides.

Please direct any questions to the Decatur County Extension Office at (229) 248-3033.