Controlling Quack Grass is not an easy feat because 2-4-D commonly found in weed control agents is not effective for controlling this weed. MSMA commonly used in Crabgrass control agents is not effective either. The only way to control this nuisance is to use the active ingredient found in Zamzow’s Kleen-Up (Kleen-Up is about half the cost of Round-Up and is concentrated at a stronger solution). Prior to an application, you should mow your grass back to 2.5 to 3 inches or 3.5 in the heat of summer. Quack Grass will outgrow your turf grass. At this point, you can swipe the higher Quack Grass blades with a solution of Kleen-Up. There used to be a tool made specifically for this purpose, but I have not seen one in quite some time. You will need a small piece of sponge and a waist high stick, an old golf club works great. Attach the sponge to the stick and dip it into the Kleen-Up solution. Swipe the tops of the Quack Grass blades being careful not to drip the solution onto your turf grass. This will kill out your Quack Grass.
The next step is as important as the first. Once your Quack Grass has been successfully controlled, the areas affected will need to be reseeded. Use a quality seed such as Zamzow’s lawn blend at a rate of 8 lbs. per 1000 Sq. Ft. To do this rake the affected areas aggressively 14 days after you have applied your solution or after you have killed all the Quack Grass from that area. Next, apply your seed and cover ¼ inch with a good potting soil such as Grandma Z’s potting soil or Zamzow’s garden planter mix. After you have seeded your areas, apply an application of Zamzow’s Recharger to your entire lawn at a rate of one bag per 5000 Sq. Ft. This will not only get your new seed started but will also feed your existing turf.
Pre-emergent applications for Quack Grass are limited and often ineffective. Keeping your grass mowed short will eventually kill the Quack Grass. In the heat of summer though your lawn may not be able to tolerate the heat if it is kept short. So the “swiping” of this weedy grass is usually the best method of control.
Two more pieces of advice to keep in mind when dealing with Quack Grass, since this weed often spreads by rhizomes, pulling this grass often helps it to spread, also if you are on a pressurized irrigation system, make sure you have an in-line filter and are keeping it clean.