Mid-Summer Crabgrass: Too Late for Pre-Emergent, Act Now

The Pre-Emergent Window Is Closed

Connecticut, July: crabgrass exploding. Pre-emergent (crabgrass preventer) only works before germination (early–mid April). Applying now wastes money.

Immediate Action: Post-Emergent Control

• Ortho Weed-B-Gon Crabgrass Control (quinclorac) – spray young plants (<4 leaves).
• Available at garden centers, Home Depot, Lowe's (~$8/bottle).
• Mature crabgrass (4+ leaves) resists herbicide.

Accept This Year, Prevent Next Year

• Crabgrass is an annual—dies at first frost.
• Next year: Apply pre-emergent + fertilizer in early April (soil temp ~55°F).
• Skip May fertilizer if April had preventer.
• Fertilize: late May, early Sept, late Oct. Never summer.

Organic Alternative: Corn Gluten Meal

• 20 lbs / 1000 sq ft in early April.
• Slow-release N + pre-emergent action.
• Must hit 20 lbs rate; less = ineffective.
• Calculate lawn area: sum of rectangles (L×W).

Hand-Pulling Survivors

After pre-emergent, few plants emerge—pull them before seeding.

Bottom Line

July crabgrass: spot-spray quinclorac on young plants. Real solution: April pre-emergent (synthetic or corn gluten) every year. Mark the calendar.