How to use soil temperature for lawn care

Soil temperature helps estimate when weeds begin germinating, when cool-season roots are active, when warm-season turf is waking up, and when stress risk increases. It does not replace the product label, soil test, or grass-type calendar, but it makes timing less random.

One warm afternoon can be misleading. Look for several days of readings moving into the target window. Purdue describes crabgrass germination around 60 degrees Fahrenheit, while UMN notes cool-season root growth is optimal when soil temperatures are between 50 and 65 degrees Fahrenheit.

• Pre-emergent timing before summer annual weeds germinate.
• Spring green-up decisions for warm-season lawns.
• Seed timing and establishment expectations.
• Stress planning when soil and air temperatures rise.

Open the Soil Temperature Tracker and compare surface, 2 inch, and 6 inch readings.