This year’s battle with fleas, ticks, bagworms, grasshoppers and other insects should be coming to end soon. A new battle begins, winter weeds. September is the time to start the application of a pre-emergent weed control to the lawn. When the air temperatures start dropping the ground temperatures start cooling down, that is the time to apply a pre-emergent. For some weed germination to take place it only takes a soil temperature of 77 degrees.
When to Apply Pre-emergents
We recommend you make the application of a pre-emergent weed control on or before September 15th here in the DFW area. The best plan of action against weeds is prevention. It doesn’t matter if you use an organic or a chemical pre-emergent, either one will reduce the amount of weeds this fall. Organic pre-emergent is called Corn Gluten Meal. When used at the right time the naturally occurring proteins in corn gluten meal interfere with the ability of the newly sprouted roots to take up water, without which the plant dies before it can form more roots or leaves.
Weed Species
Dr. Christians (of Iowa State University) and his researchers have tested twenty-two common weed species for susceptibility to corn gluten meal including Black Medic, Black Nightshade, Buckhorn Plantain, Catchweed, Bedstraw, Common Lambsquarter, Curly Dock, Dandelion, Purslane, Redroot Pigweed, Velvetleaf, Annual Bluegrass, Barnyard Grass, Creeping Bentgrass, Giant Foxtail, Large Crabgrass, Orchardgrass, Quackgrass, Shattercane, Smooth Crabgrass, Wooly Cupgrass, and Yellow Foxtail. They found that corn gluten meal significantly reduced plant survival, shoot length, and root development of all tested species. Use at the rate of 20 lbs. per 1000 square feet.
There are many chemical pre-emergent’s to choose from and one containing Dimension works well in controlling weed germination. It controls some 40 types of weed seeds with the application rate of 9 lbs. per 1000 square feet.
A word of warning if organic or chemical pre-emergent are being used in a lawn area, then you will not be able to over seed the lawn with fescue, winter rye or wild flower seeds. A pre-emergent works to stop all seeds from germinating.