Weed
2,4-D pre-emergent
Spring pre-emergent timing
A pre-emergent herbicide forms a chemical barrier in the top inch of soil that stops crabgrass and other summer annual grasses as they germinate. Applied too late, it misses the germination window; applied too early, it breaks down before the seeds activate.
Read the full guide →Conditions are close to the action band. Monitor daily, the window typically opens within a few days.
Why this, why now
Safety details (REI, air-temp ceiling, pre-rain)
Conditions are not yet in the action band. The guidance below describes the safety constraints to plan around when the window opens.
Keep pets and children off treated areas for 12 hours after application.
Air temperatures above 90°F can volatilize the product or stress the lawn. Wait for cooler conditions.
Apply at least 24 hours before forecast rain so the product binds before runoff.
Reseeding restriction: If you reseeded in the last 16 weeks, do NOT apply.