Problems Re-Sodding Lawns With Crabgrass

Problems with Crabgrass

• Crabgrass seeds germinate in early spring when soil temperatures reach 60 degrees Fahrenheit. This annual grassy weed reproduces through seeds even when maintained at 1/4 of an inch. Furthermore, crabgrass grows vigorously and competes with turf grass. Oftentimes, gardeners find that they must renovate their lawns when crabgrass growth has exceeded 50 percent of their lawn. Laying sod over crabgrass will not make it go away. Newly laid sod must compete with this grassy weed while it is trying to develop a strong root system. The result is a newly sodded lawn with a poor root system, which encourages weed growth.

Herbicide

• Use an herbicide that contains glyphosate. Glyphosate is commonly used because it leaves little soil residue. Herbicides that leave soil residue kill sod as soon as it is laid. When used correctly, glyphosate will kill crabgrass weeds within a few days. Choose a dry day to spray your crabgrass. Avoid spraying glyphosate around ornamental plants. This herbicide kills any plant that it comes in contact with.

Removing Crabgrass

• Wait five to 14 days to lay sod after spraying a herbicide. Monitor the area and reapply the herbicide to crabgrass unaffected by the initial application. Dig up the dead crabgrass from the lawn and throw it away or burn it. Avoid composting crabgrass to prevent spreading seeds all over the lawn. Plan on re-sodding your lawn immediately after removing crabgrass since weeds take advantage of bare soil. Work a starter fertilizer with a high percentage of phosphorous into the first 2 to 4 inches of topsoil right before re-sodding.

Re-Sodding

• Install your sod as soon as it is delivered. Sod left out in the sun will dry out and not establish. Apply a pre-emergent herbicide the following spring to prevent crabgrass seeds from growing back. Use a pre-emergent herbicide that contains active ingredients such as bensulide, oryzalin or pendimethalin. Apply the pre-emergent spray evenly over the lawn even in the areas where crabgrass wasn't growing. Water the lawn to help the herbicide penetrate the soil.