How to Apply Crab Grass Preventer

Nothing is more frustrating than a lawn filled with crabgrass. There are preemergence herbicides, both liquid and granular, that will target only unwanted grasses such as crabgrass and prevent them from germinating. They won't harm the grass you want to keep. With a little work and patience, your yard will soon be looking good again.

Things You'll Need

• Preemergence herbicide for lawns
• Hose
• Fertilizer spreader
• Pump-up sprayer

Instructions

Liquid Crabgrass Preventer

1. Apply a crabgrass herbicide preventer to your lawn before the temperatures reach a constant of 60 degrees. Crabgrass will not germinate in cold weather because it is a warm-season annual. By applying the herbicide early in the season you'll have better control of any crabgrass that appears when the weather warms.

2. Choose a liquid crabgrass herbicide preventer. Some are available in a concentrated form; you will have to mix it yourself and use your own pump-up sprayer. You can also buy it already premixed and ready for application. The concentrate is a few dollars more that the premixed, but you'll get more applications for your money by mixing your own.

3. Turn off your sprinkler system for at least a day after applying the herbicide. It's also best to apply the crabgrass herbicide on a day that no rain is expected. The water will wash the preemergence herbicide away and the product will be less effective.

4. Spray the areas of your lawn with the preemergence herbicide, making sure to saturate all areas of the grass. With most herbicides, you should start to see results within the first 24 hours if crabgrass has already started to germinate. You may need to reapply the herbicide in a week if some crabgrass still remains.

Granular Crabgrass Killer

1. Choose preemergence herbicide granules that are specifically designed to deal with crabgrass. Read the back of the package to make sure the grass you want to prevent and eliminate is listed. Otherwise, you might end up killing grass you want to keep.

2. Set your spreader to the number listed on the package of herbicide granules. Fertilizer spreaders have different settings that allow the granular product to be released at a certain rate. You'll want to make sure you apply just enough. If you apply too little, the crabgrass might not be prevented or eliminated, and if you apply too much, you may burn or kill the grass you wish to keep.

3. Water the grass well, once you've applied the granular herbicide. This will help dissolve the granules so they will be able to leach into the soil and prevent and kill any crabgrass.

4. Expect to see results in a few days if the crabgrass has started to germinate. If after several weeks you still have a crabgrass problem, you can reapply the granular herbicide wherever it is needed.

Tips & Warnings

• Overwatering your lawn can make the crabgrass problem worse. Maintaining a healthy lawn will prevent crabgrass from germinating. Mow at a height of 2.5 to 3 inches to prevent crabgrass from entering the lawn.

References

• University of IIlinois--Preventing Crabgrass