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Bill Starr: Control crabgrass before it controls you

I believe the old Groundhog might be right, at least I hope so; it seems spring will be just around the corner. I noticed some red maples beginning to swell the other day driving down the road. When I start thinking about spring, one thing comes to mind: crabgrass!
Well actually a lot of things come to mind, but I know that I am going to get plenty of calls about controlling crabgrass. I know it seems a little cold but now is when we need to make our plan so that we don’t have to battle crabgrass all summer.
There are several pre-emergence products out there that will control crabgrass, as well as other annual grasses and some broadleaf weeds. The key is timing. If you wait until you see crabgrass, these products will not work.
They have to be applied to the soil and activated by either irrigation or rainfall. They either work by preventing germination or by killing the newly germinated seed. Therefore these products should not be used on newly seeded lawns or areas where other seeds have been spread.
Some of the products available are Surflan, Balan, Crabgrass Preventer, Halts, and XL.  If it says it is a crabgrass herbicide it is most likely one of these products. Since crabgrass germinates in soils with temperatures around 60 percent, we need to put out these herbicides before this occurs. You can monitor soil temperature online at the following web site http://www.griffin.uga.edu/aemn/cgi-bin/AEMN.pl?site=GAHW, or you can do it yourself with a meat thermometer.
If you don’t care about monitoring the temperature, you can just apply your product of choice around March 1. I would rather get the product out a little too early because if you are too late you won’t get any control with the above products. Depending on the level of infestation you may also choose to make a second application in early summer, but this should only be done according to the label.
If you get caught and don’t get your pre-emergence herbicide out, there are some products that can be used to control crabgrass, but that is for a different article. It s a lot easier to prevent crabgrass than it is to try and treat it once it s growing. This can be extremely difficult depending on what type grass you have.

Bill Starr is Sumter County Extension coordinator, University of Georgia Cooperative Extension Service. Contact him at 229-924-4476.