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Soil temperature tracker
Lawn timing runs on soil temperature, not the calendar. Enter your ZIP to see live soil temps at three depths, your crabgrass pre-emergent window, and what to do for your grass type.
Temperature says when to act; a soil test says what to put down. Find your state's university soil testing lab on the interactive map.
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Common questions
- What soil temperature does bermuda grass need to break dormancy?
- Bermuda grass active growth and visible greenup require consistent soil temperatures approaching 65°F. Texas A&M AgriLife Extension notes that green-up and recovery begin when soil temperature reaches 65°F at depth with nighttime temperatures consistently above 60°F. A full fertilizer and PGR program is appropriate once active canopy growth is confirmed. Use the pre-emergent window, when 2-inch soil reaches 50-55°F, as a crabgrass prevention signal, not as a bermuda greenup trigger.
- What soil temperature should I use for pre-emergent timing?
- Apply crabgrass pre-emergent when 2-inch soil temperature reaches 50-55°F for 3-5 consecutive days. For bermuda and St. Augustine lawns this window typically opens in late winter or early spring. Applying after soil consistently exceeds 55°F risks missing the window for summer annual weeds.
- What is the ideal soil temperature for zoysia grass?
- Zoysia breaks dormancy slightly later than bermuda, typically when 2-inch soil temperature reaches 55-65°F. Apply pre-emergent before soil hits 65°F. A full fertilizer and PGR program is appropriate once soil consistently exceeds 65°F and visible greenup is confirmed, since zoysia often shows green later than bermuda at the same soil temperature.
- What soil temperature is too hot for lawn applications?
- Above 80°F soil temperature, warm-season grasses are in full summer growth but stress risk increases. Kansas State Extension specifically warns against applying elemental sulfur to established turfgrass at air temperatures of 80°F or higher due to burn risk. University of Nebraska-Lincoln turfgrass research notes that cool-season grass growth stops when soil temperature in the surface inch reaches 77-80°F, with an energy deficit at 80-85°F. Monitor chinch bug pressure on St. Augustine during peak summer, University of Georgia extension research shows development accelerates significantly at 83°F.
Stop checking. Get alerted.
The app watches your soil temperature daily and notifies you when your pre-emergent and fertilizer windows open. Free to download.
Research and extension sources
- Open-Meteo
- Texas A&M AgriLife Extension: Spring Transition in Bermudagrass, 65°F greenup threshold
- University of Minnesota Extension: Crabgrass, 55°F pre-emergent timing
- Penn State Extension: Smooth Crabgrass and Large Crabgrass, germination temperature
- Penn State Extension: Cool-Season Turfgrasses, 50-65°F root growth range
- NC State Extension: St. Augustinegrass Lawn Maintenance Calendar
- Clemson Extension: St. Augustinegrass Maintenance Calendar, 65°F greenup
- Kansas State Extension: Acidifying Your Soil, 80°F limit for elemental sulfur on turfgrass
- University of Nebraska-Lincoln Turfgrass Science: High Temperatures and Cool-Season Grasses
- University of Georgia Extension: Southern Chinch Bug Biology and Management