Sioux City, IA Lawn Care Calendar
In a typical year, put down crabgrass preventer in Sioux City between Apr 15 and May 12. The best time to overseed is between Jul 31 and Sep 19. The last spring frost usually comes around Apr 24. Most lawns here are cool-season grass (tall fescue, Kentucky bluegrass, ryegrass).
Typical lawn care dates in Sioux City
| Task | Typical window |
|---|---|
| Crabgrass preventer (pre-emergent)Crabgrass sprouts once soil stays above 55°F. Apply when soil reaches 50°F, before that happens. | Apr 15 – May 12 |
| Spring fertilizerA light feeding once soil warms past 55°F and the grass is actively growing. | May 5 – Jun 9 |
| Overseeding & seedingLate summer to early fall: seedlings need about 6–10 weeks of growth before the first frost. | Jul 31 – Sep 19 |
| Fall fertilizerThe most important feeding for cool-season grass, from early fall until soil cools to about 45°F. | Aug 19 – Oct 29 |
Median dates, 2016–2025, from NOAA weather data for Sioux City. This year's dates can differ by a few weeks.
Month-by-month lawn care in Sioux City
- JanuaryNo treatments due; mow as needed.
- FebruaryNo treatments due; mow as needed.
- MarchNo treatments due; mow as needed.
- AprilCrabgrass preventer (pre-emergent)
- MayCrabgrass preventer (pre-emergent)Spring fertilizer
- JuneSpring fertilizer
- JulyOverseeding & seeding
- AugustOverseeding & seedingFall fertilizer
- SeptemberOverseeding & seedingFall fertilizer
- OctoberFall fertilizer
- NovemberNo treatments due; mow as needed.
- DecemberNo treatments due; mow as needed.
Soil temperature in Sioux City by month
Average soil temperature 4 inches down, estimated from 2016–2025 weather. It bottoms out in January at 20°F and peaks in July at 75°F. Crabgrass preventer goes down when it reaches 50°F, usually around Apr 15.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 20°F | 23°F | 37°F | 46°F | 59°F | 72°F | 75°F | 72°F | 67°F | 53°F | 38°F | 27°F |
Sioux City lawn timing, year by year
Over the last 10 years, soil in Sioux City reached 50°F, the signal for crabgrass preventer, as early as Apr 5 (2021) and as late as May 7 (2022): 32 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 (Apr 24) and first fall frost (Oct 14), the growing season lasts about 173 days.
| Year | Crabgrass window opened | Last spring frost | First fall frost |
|---|---|---|---|
| 2025 | Apr 13 | Apr 19 | Oct 22 |
| 2024 | Apr 13 | Apr 22 | Oct 14 |
| 2023 | Apr 10 | Apr 25 | Oct 27 |
| 2022 | May 7 | Apr 27 | Oct 8 |
| 2021 | Apr 5 | May 5 | Oct 22 |
| 2020 | Apr 23 | May 11 | Oct 2 |
| 2019 | Apr 21 | Apr 19 | Oct 12 |
| 2018 | Apr 28 | Apr 21 | Oct 13 |
| 2017 | Apr 14 | May 2 | Oct 11 |
| 2016 | Apr 15 | Apr 13 | Oct 13 |
Estimated from daily temperatures for Sioux City. A dash means it didn't happen that year.
Frequently asked questions
When should I apply pre-emergent in Sioux City?
In a typical year, between Apr 15 and May 12. 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 Sioux City?
Early fall, typically Jul 31 – Sep 19, while soil cools from 65°F toward 50°F.
When is the last frost in Sioux City?
The median last spring frost is Apr 24 and the median first fall frost is Oct 14 (2016–2025).
How long is the growing season in Sioux City?
About 173 days, from the median last spring frost on Apr 24 to the median first fall frost on Oct 14 (2016–2025).
Lawn care guides
More Iowa lawn calendars
Nearby cities in other states
- Sioux Falls, SD 74 miles away · crabgrass preventer Apr 19 – May 15
- Omaha, NE 89 miles away · crabgrass preventer Apr 9 – Apr 29
- Lincoln, NE 118 miles away · crabgrass preventer Apr 10 – Apr 29
- Grand Island, NE 148 miles away · crabgrass preventer Apr 14 – May 3