Best days to apply pre-emergent in Miami, FL this week

This week in Miami

Fairsky is not a substitute for official warnings. For warnings, go to weather.gov. Verdicts are guidance, not guarantees. Your product's label always wins.

When putting down pre-emergent usually works in Miami

• On 1991–2020 averages, Miami reaches 200 growing degree days (base 50°F, counted from January 1) during January. Purdue's turf research ties crabgrass emergence to about 200 GDD.
• Fairsky aims to have pre-emergent down by about 150 GDD, which the averages reach during January. Real years run early or late, which is why the live soil estimate above matters.
• Miami's normal daily mean temperature is 50°F or warmer even in January, so crabgrass timing here doesn't follow the northern spring calendar; check your local extension service.

Station: Miami Beach (NOAA NCEI USW00092811), about 8 km from central Miami. “Rain days” count days with 0.10" or more of precipitation.

The rules we check

• Soil temperature is estimated from the average air temperature over about five days (past and forecast); Fairsky labels it as an estimate.
• Spring: below about 50°F soil it's too early; roughly 50–58°F is prime time; up to 65°F is late but not lost; above that, crabgrass is already up.
• Rain helps: about a quarter to half an inch in the next three days waters it in. More than an inch in the next 24 hours means hold off, since a downpour can wash granules away. (Fairsky default: no source gave a number)
• Fall (August–October, soil 55–70°F): a window for winter weeds like henbit, chickweed and Poa annua.
• Wind under 20 mph while spreading. (Fairsky default: no source gave a number)

Your product's label always wins. Labels differ by product; in the app you can enter your label's temperature range and rain-free hours, and the verdict uses them instead.

Sources: Purdue Turf: pre-emergence timing · K-State: predicting crabgrass emergence · Iowa State: how to control crabgrass

More home and yard jobs in Miami

• Stain a deckDeck and fence stain: 50–90°F, dry wood, 24 rain-free hours after.
• Paint a house exteriorExterior latex paint: 40°F and up, 5°F above the dew point, 4 dry hours after.
• Pour concreteConcrete: 40–85°F, no rain for 24 hours, no freezing for 48.
• Spray weedsWeed killer: 3–10 mph wind, 45–85°F, 4 rain-free hours after.
• Plant grass seedCool-season grass seed: soil about 50–65°F, highs 60–80°F, no washout rain.
• Seal a drivewayAsphalt sealcoat: 55°F and rising, 50°F overnight, 36 rain-free hours.
• Cover plants for frostFrost watch: cover at 34°F, or 36°F on clear, calm nights; 28°F is a hard freeze.

The app covers 47 activities in all, from mowing to a round of golf: see every activity and its rules.

Apply pre-emergent in nearby cities

• Cape Coral, FL122 miles away
• Melbourne, FL162 miles away
• Sarasota, FL181 miles away
• Lakeland, FL191 miles away
• Orlando, FL205 miles away
• Tampa, FL206 miles away

All apply pre-emergent cities: Apply pre-emergent, by city · Home and yard in Florida