Crabgrass After Fertilizer Burn: Wait and Pre-Emergent

After a massive fertilizer spill killed a lawn, the homeowner seeded, but crabgrass took over the dead zones. The weeds germinated from seed in the open soil—pH change wasn’t the cause.

Crabgrass is an annual that dies at first frost. Fighting it now is impractical (hand-pulling only). The solution: apply a pre-emergent herbicide (e.g., Scotts Turf Builder with Halts) in early spring when forsythia blooms (soil ~55°F). This prevents crabgrass seeds from germinating. Note: you cannot overseed in spring if you use pre-emergent; wait until fall.

For now, mow high, water deeply once a week, and let the crabgrass die with frost. Next spring, pre-emergent + fall overseeding will restore a clean lawn.