Philadelphia, PA Lawn Care Calendar
In a typical year, put down crabgrass preventer in Philadelphia between Mar 30 and Apr 20. The best time to overseed is between Sep 2 and Oct 22. The last spring frost usually comes around Mar 31. Most lawns here are cool-season grass (tall fescue, Kentucky bluegrass, ryegrass).
Typical lawn care dates in Philadelphia
| 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 20 |
| Spring fertilizerA light feeding once soil warms past 55°F and the grass is actively growing. | Apr 13 – May 18 |
| Overseeding & seedingLate summer to early fall: seedlings need about 6–10 weeks of growth before the first frost. | Sep 2 – Oct 22 |
| Fall fertilizerThe most important feeding for cool-season grass, from early fall until soil cools to about 45°F. | Sep 28 – Nov 25 |
Median dates, 2016–2025, from NOAA weather data for Philadelphia. This year's dates can differ by a few weeks.
Month-by-month lawn care in Philadelphia
- 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.
- AugustNo treatments due; mow as needed.
- SeptemberOverseeding & seedingFall fertilizer
- OctoberOverseeding & seedingFall fertilizer
- NovemberFall fertilizer
- DecemberNo treatments due; mow as needed.
Soil temperature in Philadelphia by month
Average soil temperature 4 inches down, estimated from 2016–2025 weather. It bottoms out in January at 36°F and peaks in July at 81°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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 36°F | 38°F | 45°F | 55°F | 64°F | 74°F | 81°F | 78°F | 72°F | 61°F | 49°F | 39°F |
Philadelphia lawn timing, year by year
Over the last 10 years, soil in Philadelphia reached 50°F, the signal for crabgrass preventer, as early as Mar 10 (2016) and as late as Apr 14 (2018): 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 31) and first fall frost (Nov 16), the growing season lasts about 230 days.
| Year | Crabgrass window opened | Last spring frost | First fall frost |
|---|---|---|---|
| 2025 | Mar 15 | Mar 9 | Nov 11 |
| 2024 | Mar 13 | Mar 24 | Nov 30 |
| 2023 | Apr 4 | Mar 20 | Nov 13 |
| 2022 | Mar 18 | Mar 30 | Nov 18 |
| 2021 | Mar 25 | Apr 2 | Nov 24 |
| 2020 | Apr 6 | Apr 19 | Nov 19 |
| 2019 | Apr 7 | Apr 1 | Nov 9 |
| 2018 | Apr 14 | Apr 9 | Nov 11 |
| 2017 | Apr 4 | Mar 24 | Nov 11 |
| 2016 | Mar 10 | Apr 10 | Dec 9 |
Estimated from daily temperatures for Philadelphia. A dash means it didn't happen that year.
Frequently asked questions
When should I apply pre-emergent in Philadelphia?
In a typical year, between Mar 30 and Apr 20. 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 Philadelphia?
Early fall, typically Sep 2 – Oct 22, while soil cools from 65°F toward 50°F.
When is the last frost in Philadelphia?
The median last spring frost is Mar 31 and the median first fall frost is Nov 16 (2016–2025).
How long is the growing season in Philadelphia?
About 230 days, from the median last spring frost on Mar 31 to the median first fall frost on Nov 16 (2016–2025).
Lawn care guides
More Pennsylvania lawn calendars
Nearby cities in other states
- Cherry Hill, NJ 8 miles away · crabgrass preventer Mar 30 – Apr 27
- Wilmington, DE 25 miles away · crabgrass preventer Mar 30 – Apr 24
- Trenton, NJ 29 miles away · crabgrass preventer Apr 8 – Apr 27
- Newark, DE 36 miles away · crabgrass preventer Apr 2 – Apr 27