Chicago, IL Lawn Care Calendar
In a typical year, put down crabgrass preventer in Chicago between Apr 19 and May 13. The best time to overseed is between Aug 24 and Oct 13. The last spring frost usually comes around Apr 6. Most lawns here are cool-season grass (tall fescue, Kentucky bluegrass, ryegrass).
Typical lawn care dates in Chicago
| 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 19 – May 13 |
| Spring fertilizerA light feeding once soil warms past 55°F and the grass is actively growing. | May 6 – Jun 10 |
| Overseeding & seedingLate summer to early fall: seedlings need about 6–10 weeks of growth before the first frost. | Aug 24 – Oct 13 |
| Fall fertilizerThe most important feeding for cool-season grass, from early fall until soil cools to about 45°F. | Sep 10 – Nov 9 |
Median dates, 2016–2025, from NOAA weather data for Chicago. This year's dates can differ by a few weeks.
Month-by-month lawn care in Chicago
- 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
- JulyNo treatments due; mow as needed.
- AugustOverseeding & seeding
- SeptemberOverseeding & seedingFall fertilizer
- OctoberOverseeding & seedingFall fertilizer
- NovemberFall fertilizer
- DecemberNo treatments due; mow as needed.
Soil temperature in Chicago by month
Average soil temperature 4 inches down, estimated from 2016–2025 weather. It bottoms out in January at 28°F and peaks in July at 76°F. Crabgrass preventer goes down when it reaches 50°F, usually around Apr 19.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 28°F | 30°F | 40°F | 48°F | 58°F | 70°F | 76°F | 75°F | 70°F | 58°F | 44°F | 33°F |
Chicago lawn timing, year by year
Over the last 10 years, soil in Chicago reached 50°F, the signal for crabgrass preventer, as early as Apr 5 (2021) and as late as May 9 (2022): 34 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 6) and first fall frost (Nov 7), the growing season lasts about 215 days.
| Year | Crabgrass window opened | Last spring frost | First fall frost |
|---|---|---|---|
| 2025 | Apr 19 | Apr 9 | Nov 10 |
| 2024 | Apr 9 | Mar 28 | Nov 21 |
| 2023 | Apr 10 | Apr 2 | Oct 31 |
| 2022 | May 9 | Mar 30 | Nov 14 |
| 2021 | Apr 5 | Apr 22 | Nov 4 |
| 2020 | Apr 28 | May 9 | Oct 31 |
| 2019 | Apr 22 | Apr 2 | Nov 1 |
| 2018 | May 1 | Apr 18 | Oct 21 |
| 2017 | Apr 15 | Mar 23 | Nov 10 |
| 2016 | Apr 18 | Apr 10 | Nov 20 |
Estimated from daily temperatures for Chicago. A dash means it didn't happen that year.
Frequently asked questions
When should I apply pre-emergent in Chicago?
In a typical year, between Apr 19 and May 13. 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 Chicago?
Early fall, typically Aug 24 – Oct 13, while soil cools from 65°F toward 50°F.
When is the last frost in Chicago?
The median last spring frost is Apr 6 and the median first fall frost is Nov 7 (2016–2025).
How long is the growing season in Chicago?
About 215 days, from the median last spring frost on Apr 6 to the median first fall frost on Nov 7 (2016–2025).
Lawn care guides
More Illinois lawn calendars
Nearby cities in other states
- South Bend, IN 72 miles away · crabgrass preventer Apr 19 – May 8
- Milwaukee, WI 81 miles away · crabgrass preventer Apr 21 – May 22
- Kalamazoo, MI 108 miles away · crabgrass preventer Apr 20 – May 7
- Madison, WI 122 miles away · crabgrass preventer Apr 20 – May 16