Match fertilizer timing to soil temperature not the calendar

What to Do

Use a soil thermometer to guide fertilizer timing rather than calendar dates. For cool-season grasses, wait until soil temperature at 4-inch depth consistently reaches 55°F. For warm-season grasses, wait until soil hits 65-70°F.

Why It Works

Grass growth and nutrient uptake are driven by soil temperature, not air temperature or calendar dates. A warm week in March can tempt homeowners to fertilize, but cold soil means the grass cannot absorb the nutrients and they wash away or feed weeds.

Tips

• Inexpensive soil thermometers cost $10-15 at garden centers.
• Check your local university extension website for real-time soil temperature maps — many states publish them.