weeds in a lawn

Sunny, warmer days mean the weeds are going into overdrive.


Though the cold weather is not too long past, seasonal moisture and warmth may have caused weeds to take over your lawn.

Common lawn weeds grow quickly, flower rapidly and reproduce prolifically. The myriad of weeds include bristly mallow, burclover, dichondra, Carolina geranium, bedstraw, chickweed, filaree, hairy buttercup, hedge parsley, horseweed, shepherd’s purse, Virginia buttonweed ... you get the picture.

Lawns take management. Having a plan with regular fertilization and weed control built in is the easiest and most efficient way to keep it that way. At the LSU AgCenter website you can download an e-copy of the “Louisiana Lawns Best Management Practices” publication for free or order a hard copy lsuagcenter.com). It is full of information that will help you formulate a plan and put it into practice.

The weeds you are seeing now are winter annuals and perennials that include broadleaf weeds and grasses. An effective way to kill winter weeds is to use both atrazine and Trimec-type herbicides on the same lawn within a week of each other. For example, you could spray Trimec, Weed B Gon or Weed Free Zone over a weekend and then follow up this application with atrazine a few days later.

Trimec-type herbicides are taken up mainly through leaf absorption, while atrazine is mainly absorbed by the root system. This two-pronged attack can be very effective on winter weeds since neither alone will control all the weeds that are showing up now. Trimec-type herbicides contain 2,4-D, dicamba and mecoprop as active ingredients and are very effective against broadleaf weeds. Atrazine has both pre-emergent and post-emergent activity.

As with all pesticides you use, read the label before purchasing the product. Make sure it will do what you want it to do and that you have the proper application equipment and personal protective equipment that may be required.

Once you purchase the product, follow the directions exactly. They are written to ensure you get the most effective results with the least environmental impact. And remember, “The Label Is The Law."

For many, using chemicals on your lawn or garden is simply unthinkable. If you are in that camp, you can still have a nice-looking lawn, but it will take a lot more labor and care. There is simply no way to keep the weeds out. However, use of products containing corn gluten has shown some activity as a pre-emergent.

Post-emergence care will come down to hand removal on a regular basis and keeping the lawn well-nourished so the turf can outcompete the weeds – or at least have an equal chance.

Pull weeds when the soil is moist so the task is easier and you can remove more of the root system. If dealing with perennials, just keep pulling until the roots die of starvation.

Of course there's another lawn care approach: If it’s green just mow it, and be happy it’s there -- whatever it is.

You can get a free subscription to the electronic version of the GNOGardening Newsletter by sending a request to GNOGardening@AgCenter.LSU.edu. Send your gardening questions to AGCenter@theadvocate.com. Start making plans for the 2018 New Orleans Spring Garden Show April 7-8 at the New Orleans Botanical Gardens in City Park.

If I am composting, how do I know when it is finished and ready to use? Kim

Firstly, compost piles should stirred or turned regularly. The microbiological breakdown of the organic matter is an exothermic process so the pile will heat up as activity increases. If you have a soil thermometer, you can check the temperature regularly – it should follow a bell curve. When cool down stabilizes, it’s finished. Another visual method is, when everything is broken down to the point that you can no longer recognize what it once was, it is ready to use.

Joe Willis and Anna Timmerman are Louisiana State University agricultural extension agents. Questions? Email agcenter@theadvocate.com.