Wilmington, DE Lawn Care Calendar
In a typical year, put down crabgrass preventer in Wilmington between Mar 30 and Apr 24. The best time to overseed is between Aug 29 and Oct 18. The last spring frost usually comes around Apr 3. Most lawns here are cool-season grass (tall fescue, Kentucky bluegrass, ryegrass).
Typical lawn care dates in Wilmington
| Task | Typical window |
|---|---|
| Crabgrass preventer (pre-emergent)Crabgrass sprouts once soil stays above 55°F. Apply when soil reaches 50°F, before that happens. | Mar 30 – Apr 24 |
| Spring fertilizerA light feeding once soil warms past 55°F and the grass is actively growing. | Apr 17 – May 22 |
| Overseeding & seedingLate summer to early fall: seedlings need about 6–10 weeks of growth before the first frost. | Aug 29 – Oct 18 |
| Fall fertilizerThe most important feeding for cool-season grass, from early fall until soil cools to about 45°F. | Sep 20 – Nov 20 |
Median dates, 2016–2025, from NOAA weather data for Wilmington. This year's dates can differ by a few weeks.
Month-by-month lawn care in Wilmington
- JanuaryNo treatments due; mow as needed.
- FebruaryNo treatments due; mow as needed.
- MarchCrabgrass preventer (pre-emergent)
- AprilCrabgrass preventer (pre-emergent)Spring fertilizer
- MaySpring fertilizer
- JuneNo treatments due; mow as needed.
- 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 Wilmington by month
Average soil temperature 4 inches down, estimated from 2016–2025 weather. It bottoms out in January at 35°F and peaks in July at 79°F. Crabgrass preventer goes down when it reaches 50°F, usually around Mar 30.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 35°F | 37°F | 44°F | 54°F | 63°F | 72°F | 79°F | 77°F | 71°F | 60°F | 47°F | 38°F |
Wilmington lawn timing, year by year
Over the last 10 years, soil in Wilmington reached 50°F, the signal for crabgrass preventer, as early as Mar 10 (2016) and as late as Apr 24 (2018): 45 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 3) and first fall frost (Nov 12), the growing season lasts about 223 days.
| Year | Crabgrass window opened | Last spring frost | First fall frost |
|---|---|---|---|
| 2025 | Mar 17 | Apr 9 | Nov 11 |
| 2024 | Mar 13 | Mar 24 | Nov 30 |
| 2023 | Apr 5 | Mar 21 | Nov 2 |
| 2022 | Mar 19 | Mar 30 | Nov 15 |
| 2021 | Mar 25 | Apr 3 | Nov 14 |
| 2020 | Apr 6 | Apr 19 | Nov 18 |
| 2019 | Apr 8 | Apr 2 | Nov 4 |
| 2018 | Apr 24 | Apr 11 | Nov 11 |
| 2017 | Apr 4 | Mar 24 | Nov 11 |
| 2016 | Mar 10 | Apr 10 | Nov 12 |
Estimated from daily temperatures for Wilmington. A dash means it didn't happen that year.
Frequently asked questions
When should I apply pre-emergent in Wilmington?
In a typical year, between Mar 30 and Apr 24. 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 Wilmington?
Early fall, typically Aug 29 – Oct 18, while soil cools from 65°F toward 50°F.
When is the last frost in Wilmington?
The median last spring frost is Apr 3 and the median first fall frost is Nov 12 (2016–2025).
How long is the growing season in Wilmington?
About 223 days, from the median last spring frost on Apr 3 to the median first fall frost on Nov 12 (2016–2025).
Lawn care guides
More Delaware lawn calendars
Nearby cities in other states
- Philadelphia, PA 25 miles away · crabgrass preventer Mar 30 – Apr 20
- Cherry Hill, NJ 31 miles away · crabgrass preventer Mar 30 – Apr 27
- Lancaster, PA 45 miles away · crabgrass preventer Apr 8 – Apr 24
- Trenton, NJ 53 miles away · crabgrass preventer Apr 8 – Apr 27