How to Eradicate Annual & Perennial Crabgrass

Pull the crabgrass weeds before they flower and set seed, which begins in July and continues until the first frost. If you wait until the seeds form, you will only spread the crabgrass seeds as you pull the weed. Moisten the ground before pulling crabgrass, and try to remove all the crabgrass root system. You may have to dig the soil with a garden fork to completely remove the root. Crabgrass flowers appear 18 to 14 inch apart on a long, spiky stem.

Mow the crabgrass and surrounding grass to no higher than 3 inches. If the crabgrass is annual, it won’t come back next year and it won`t make seeds.

Spray with a pre-emergent herbicide to prevent the crabgrass seeds from germinating. Pre-emergent herbicides inhibit cell division in the crabgrass root system. Use early in the spring before the crabgrass seeds germinate. Mix and follow label directions on the pre-emergent herbicide you use for best results.

Spray with a post-emergent herbicide in the spring or fall when the air temperature is 65 to 85 degrees F. You may need to repeat the post-emergent herbicide application, but keep applications 10 to 14 days apart. Post-emergent herbicides work best when the crabgrass has three to five leaves. If you wait longer, the crabgrass is harder to eradicate. Mix and follow label directions on the post-emergent herbicide you use.

Video: Tall Fescue Grass - Expert Lawn Care Turf Tips

Pour vinegar onto the crab grass. Vinegar is in almost every kitchen and works as a weed killer. Vinegar is non-selective, so it will kill whatever vegetation it meets. Vinegar is a safe alternative to using chemical herbicides.

Video: Weed Reaper Grass Control

Fertilize your lawn in the spring two to three times using a 20-10-10 fertilizer. Do not fertilize in the hot summer months, or your weeds will benefit. Read and follow all label directions for the fertilizer you apply.