Spring · Lawn · Updated September 2026
Beat crabgrass: the late-February pre-emergent window
Crabgrass sprouts once Austin soil hits about 55°F. Here's why the spring pre-emergent goes down in late February and what it prevents.
Crabgrass is a summer annual. It dies every fall and comes back every spring from seed. That makes it one of the easiest weeds to prevent and one of the hardest to fix once it's up.
The timing
Crabgrass seed starts sprouting when soil temperatures reach about 55°F. In Austin that's usually early March, so the spring pre-emergent goes down in late February to early March. Our spring PPF treatment combines pre-emergent with post-emergent for winter weeds already up, plus fertilizer for green-up.
What it stops
- Crabgrass and goosegrass
- Grassburs (sandburs)
- Spurge and purslane
One important exception
Crabgrass that's already growing in St. Augustine can't be treated without hurting the lawn. That's why prevention matters so much for St. Augustine owners.
Help it work
- Water it in within 48 hours if there's no rain.
- Mow high. Thick, tall turf shades out weed seeds.
- Don't scalp the lawn in spring.
