THE BEST Crabgrass Killer Products (Updated July 2022 ) Top Post Emergent Crabgrass Herbicides Lawn Phix

THE 5 BEST Crabgrass Killers (Updated July 2022). Crabgrass is an invasive annual weed that can quickly get out of hand if not properly prevented using crabgrass preventers and pre-emergent herbicides,or killing crabgrass using post-emergent herbicide weed killer. Crabgrass will begin to germinate when the soil temperatures reach approximately 55 degrees for four or more consecutive days and continue to germinate throughout the spring and early summer months as the ground temps approach 70 degrees.