Weed control on warm-season lawns

Why summer works

A warm-season lawn growing at full speed recovers quickly from the mild stress a selective herbicide causes, and fills the gaps left by dead weeds. Treating weeds while the lawn is dormant or just greening up is riskier and less effective.

How

• Identify the weed first: broadleaf (such as spurge or clover), grassy (crabgrass, goosegrass) or sedge (nutsedge). Each needs a different product.
• Use a selective post-emergent herbicide authorized for your grass type in your country. Some products safe on Bermuda damage St. Augustine or Centipede, so check the label.
• Spot-treat rather than blanket-spraying.
• Avoid application above about 30 °C (85–90 °F), when both weeds and grass are stressed.
• Water the lawn a day or two before, so it is not drought-stressed.

Prevent the next round

Weeds that survive summer usually started in thin spots. A dense lawn at the right height (see mowing height) and a timely spring pre-emergent reduce the need for summer treatment.