AMERICUS —

If you pay any attention to the groundhog and depending on which one you chose to believe; the one in Georgia predicted six more weeks of winter, the national groundhog in Pennsylvania predicted an early spring. I hope “Ol Phil” is right!!

I noticed some red maples beginning to swell the other day driving down the road, so my guess is that we will have an early Spring. When I start thinking about spring one thing comes to mind….  Crabgrass!

 Well actually a lot of things come to mind (especially fishing), 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. These herbicides work mostly by having soil activity, which persist in the soil several weeks effecting 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 the upper 50’s, we need to put out these herbicides before this occurs. Not all the germinate at one time You can monitor soil temperature online at the following web address georgiaweather.net. I use this website all the time because there is all sorts of weather related information available on this website, 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 after March 1st. 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. March 1st sounds like a good target date to me but this could vary over years depending on temperatures, rainfall, and quality of the turf. Soil temperatures will vary throughout your yard. How much is the soil shaded during the day? The thickness and height of your grass can affect this. So can trees, shrubs and buildings nearby, as well as cloudy days. The amount of moisture present, wind, and more, can also affect temperatures.

The end result is, these pesky weeds will pop up consistently over an extremely long growing season. Will the late bloomers be met with pre-emergent, or will it have worn off already? So there really is not one small window that is fitting for when to apply crabgrass preventer, just general guidelines because of the variability of how the seed germinate.

  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. Preventing crabgrass is a lot like getting the flu vaccine, the vaccine is usually effective if you get it before getting the flu, once you got the flu the course of action is much different.

 

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