Grass generally stops growing when temperatures consistently drop to about 50 to 55 degrees Fahrenheit (10 to 13 degrees Celsius) or below. The exact timing depends on the grass type and climate:
- Cool-season grasses, like fine fescue, tall fescue, and Kentucky bluegrass, slow or stop growth when temperatures fall below about 40 to 50°F (4 to 10°C). They can keep growing later into the year and sometimes even stay green through mild winters.
- Warm-season grasses, such as Bermuda, St. Augustine, and Zoysia, usually stop growing and go dormant when soil temperatures drop below 50 to 55°F. They thrive in heat but go dormant in late fall when it gets colder.
- Grass may go completely dormant during winter months when daylight shortens and temperatures are consistently low.
So, grass stops growing in the fall as air and soil temperatures cool down, entering a dormant phase until warmer temperatures return in spring. This is why lawns stop growing around late fall or early winter, depending on the location and grass type.
