How to Kill Crabgrass With Herbicide

Crabgrass is a common weed that grows in lawns. It forms in patches or large clumps. It is an annual summer plant and grows best in full sunshine. An effective way to rid your lawn of this weed is by using an herbicide. The most effective chemical herbicides for crabgrass are pre-emergent types. This means they kill germinating seeds before they break through the soil.

Things You'll Need

• Core aerator
• Pre-emergent herbicide
• Applicator appropriate for herbicide (spreader or spray applicator)
• Water hose

Instructions

1. Aerate your lawn.

2. Apply herbicide. With a pre-emergent herbicide, you will need to apply before the crabgrass germinates or spreads seeds. Follow the label for proper application. If you purchased liquid herbicide, use a spray bottle. If you purchased granular herbicide or corn gluten meal, use a spreader.

3. Water your grass after application of the herbicide.

4. Reapply if necessary. The garden store may recommend a second application to kill crabgrass that might be germinating later. Ask if it is appropriate for the product you purchased.

Tips & Warnings

• It's important to fertilizer correctly and not too often. Extra fertilizer only provides food for yard weeds.

• Let your lawn grow to the recommended height. On average, this will be 2 to 4 inches. High grass keeps weeds from growing by blocking the sunlight.

• Most weed and feed herbicides are not recommended. The best time to apply herbicides may not be the best time for fertilizing.

• You should not use the organic herbicide corn gluten meal if you or any one in your family are allergic to corn.

References

• University of California-Davis: Crabgrass
• This Old House: How to Get Rid of Weeds