St. George, UT Lawn Care Calendar
In a typical year, put down crabgrass preventer in St. George between Feb 25 and Mar 30. The best time to overseed is between Aug 28 and Oct 17. The last spring frost usually comes around Mar 3. Most lawns here are cool-season grass (tall fescue, Kentucky bluegrass, ryegrass).
Typical lawn care dates in St. George
| Task | Typical window |
|---|---|
| Crabgrass preventer (pre-emergent)Crabgrass sprouts once soil stays above 55°F. Apply when soil reaches 50°F, before that happens. | Feb 25 – Mar 30 |
| Spring fertilizerA light feeding once soil warms past 55°F and the grass is actively growing. | Mar 23 – Apr 27 |
| Overseeding & seedingLate summer to early fall: seedlings need about 6–10 weeks of growth before the first frost. | Aug 28 – Oct 17 |
| Fall fertilizerThe most important feeding for cool-season grass, from early fall until soil cools to about 45°F. | Oct 8 – Dec 1 |
Median dates, 2016–2025, from NOAA weather data for St. George. This year's dates can differ by a few weeks.
Month-by-month lawn care in St. George
- JanuaryNo treatments due; mow as needed.
- FebruaryCrabgrass preventer (pre-emergent)
- MarchCrabgrass preventer (pre-emergent)Spring fertilizer
- AprilSpring fertilizer
- MayNo treatments due; mow as needed.
- JuneNo treatments due; mow as needed.
- JulyNo treatments due; mow as needed.
- AugustOverseeding & seeding
- SeptemberOverseeding & seeding
- OctoberOverseeding & seedingFall fertilizer
- NovemberFall fertilizer
- DecemberFall fertilizer
Soil temperature in St. George by month
Average soil temperature 4 inches down, estimated from 2016–2025 weather. It bottoms out in January at 42°F and peaks in July at 89°F. Crabgrass preventer goes down when it reaches 50°F, usually around Feb 25.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 42°F | 47°F | 53°F | 62°F | 71°F | 83°F | 89°F | 87°F | 79°F | 66°F | 53°F | 43°F |
St. George lawn timing, year by year
Over the last 10 years, soil in St. George reached 50°F, the signal for crabgrass preventer, as early as Feb 5 (2025) and as late as Mar 12 (2023): 35 days apart. A fixed calendar date can't follow that, which is why the report above uses this year's soil temperature. Between the typical last spring frost (Mar 3) and first fall frost (Nov 11), the growing season lasts about 253 days.
| Year | Crabgrass window opened | Last spring frost | First fall frost |
|---|---|---|---|
| 2025 | Feb 5 | Feb 14 | Dec 2 |
| 2024 | Feb 19 | Feb 14 | Nov 9 |
| 2023 | Mar 12 | Apr 7 | Nov 11 |
| 2022 | Feb 11 | Mar 12 | Nov 11 |
| 2021 | Mar 6 | Mar 14 | Nov 26 |
| 2020 | Mar 4 | Feb 26 | Nov 10 |
| 2019 | Mar 2 | Feb 27 | Oct 28 |
| 2018 | Mar 10 | Mar 7 | Nov 11 |
| 2017 | Feb 8 | Mar 7 | Nov 20 |
| 2016 | Feb 13 | Feb 8 | Nov 18 |
Estimated from daily temperatures for St. George. A dash means it didn't happen that year.
Frequently asked questions
When should I apply pre-emergent in St. George?
In a typical year, between Feb 25 and Mar 30. Put it down when soil reaches 50°F, before it stays above 55°F and crabgrass starts sprouting. Early springs move this up by a week or more, so check this year's soil temperature above.
When is the best time to plant grass seed in St. George?
Early fall, typically Aug 28 – Oct 17, while soil cools from 65°F toward 50°F.
When is the last frost in St. George?
The median last spring frost is Mar 3 and the median first fall frost is Nov 11 (2016–2025).
How long is the growing season in St. George?
About 253 days, from the median last spring frost on Mar 3 to the median first fall frost on Nov 11 (2016–2025).
Lawn care guides
More Utah lawn calendars
Nearby cities in other states
- Henderson, NV 107 miles away · crabgrass preventer Feb 3 – Feb 22
- Las Vegas, NV 108 miles away · crabgrass preventer Feb 3 – Feb 17
- Flagstaff, AZ 170 miles away · crabgrass preventer May 15 – Jun 8
- Prescott, AZ 188 miles away · crabgrass preventer Apr 3 – Apr 30