Allentown, PA Lawn Care Calendar
In a typical year, put down crabgrass preventer in Allentown between Apr 10 and May 2. The best time to overseed is between Aug 14 and Oct 3. The last spring frost usually comes around Apr 12. Most lawns here are cool-season grass (tall fescue, Kentucky bluegrass, ryegrass).
Typical lawn care dates in Allentown
| 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 10 – May 2 |
| Spring fertilizerA light feeding once soil warms past 55°F and the grass is actively growing. | Apr 25 – May 30 |
| Overseeding & seedingLate summer to early fall: seedlings need about 6–10 weeks of growth before the first frost. | Aug 14 – Oct 3 |
| Fall fertilizerThe most important feeding for cool-season grass, from early fall until soil cools to about 45°F. | Sep 2 – Nov 15 |
Median dates, 2016–2025, from NOAA weather data for Allentown. This year's dates can differ by a few weeks.
Month-by-month lawn care in Allentown
- JanuaryNo treatments due; mow as needed.
- FebruaryNo treatments due; mow as needed.
- MarchNo treatments due; mow as needed.
- AprilCrabgrass preventer (pre-emergent)Spring fertilizer
- MayCrabgrass preventer (pre-emergent)Spring 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 Allentown by month
Average soil temperature 4 inches down, estimated from 2016–2025 weather. It bottoms out in January at 32°F and peaks in July at 77°F. Crabgrass preventer goes down when it reaches 50°F, usually around Apr 10.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 32°F | 34°F | 41°F | 51°F | 61°F | 70°F | 77°F | 74°F | 68°F | 57°F | 44°F | 35°F |
Allentown lawn timing, year by year
Over the last 10 years, soil in Allentown reached 50°F, the signal for crabgrass preventer, as early as Mar 10 (2016) and as late as Apr 25 (2018): 46 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 12) and first fall frost (Oct 28), the growing season lasts about 199 days.
| Year | Crabgrass window opened | Last spring frost | First fall frost |
|---|---|---|---|
| 2025 | Apr 19 | Apr 10 | Oct 27 |
| 2024 | Apr 10 | Mar 26 | Oct 28 |
| 2023 | Apr 12 | Apr 9 | Nov 2 |
| 2022 | Mar 19 | Apr 18 | Oct 19 |
| 2021 | Mar 26 | Apr 22 | Nov 3 |
| 2020 | Apr 6 | May 9 | Oct 18 |
| 2019 | Apr 8 | Apr 3 | Nov 2 |
| 2018 | Apr 25 | Apr 21 | Oct 26 |
| 2017 | Apr 11 | Apr 9 | Nov 11 |
| 2016 | Mar 10 | Apr 13 | Oct 26 |
Estimated from daily temperatures for Allentown. A dash means it didn't happen that year.
Frequently asked questions
When should I apply pre-emergent in Allentown?
In a typical year, between Apr 10 and May 2. 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 Allentown?
Early fall, typically Aug 14 – Oct 3, while soil cools from 65°F toward 50°F.
When is the last frost in Allentown?
The median last spring frost is Apr 12 and the median first fall frost is Oct 28 (2016–2025).
How long is the growing season in Allentown?
About 199 days, from the median last spring frost on Apr 12 to the median first fall frost on Oct 28 (2016–2025).
Lawn care guides
More Pennsylvania lawn calendars
Nearby cities in other states
- Trenton, NJ 47 miles away · crabgrass preventer Apr 8 – Apr 27
- Cherry Hill, NJ 52 miles away · crabgrass preventer Mar 30 – Apr 27
- Wilmington, DE 60 miles away · crabgrass preventer Mar 30 – Apr 24
- Newark, DE 65 miles away · crabgrass preventer Apr 2 – Apr 27