When to plant in Darby, PA
USDA Zone 7bHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Darby, Pennsylvania — all computed from Darby's nearest NOAA weather station.
Zone 7b means many perennials and even some tender shrubs overwinter in Darby, while your frost dates still decide when annuals go out.
Frost probability
PHILADELPHIA INTL AP · 1991–2020The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Darby’s own odds, recorded at PHILADELPHIA INTL AP.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Apr 28 | Apr 13 | Apr 1 | Oct 18 | Oct 31 | Nov 12 |
| 32°F | Apr 13 | Apr 2 | Mar 19 | Oct 30 | Nov 10 | Nov 24 |
| 28°F | Apr 3 | Mar 22 | Mar 7 | Nov 7 | Nov 23 | Dec 8 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Full-year planting calendar
Each bar is the exact window to take a planting action in Darby, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 18 km · complete 32°F normalsWhen stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.
Darby planting FAQ
When is the last spring frost in Darby, PA?
On average, the last spring frost in Darby is around April 2 (50% probability at 32°F, from 1991–2020 NOAA normals). Wait until after this date to set out tender plants like tomatoes and peppers.
When is the first fall frost in Darby, PA?
The first fall frost in Darby typically arrives around November 10 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is Darby in?
Darby is in USDA hardiness zone 7b. In zone 7b, winters are moderate — most common vegetables grow well in season.
How long is the growing season in Darby?
There are roughly 222 frost-free days in Darby (a long growing season), running from the average last frost around April 2 to the first fall frost near November 10.
When should I plant tomatoes in Darby?
In Darby, start tomato seeds indoors around February 5–February 19, then transplant seedlings outdoors around April 9 once the danger of frost has passed.
Never miss a window in Darby
An email when it’s time to start seeds, transplant, and sow — timed to Darby’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- Yeadon · 1 km
- Lansdowne · 3 km
- Drexel Hill · 5 km
- Broomall · 10 km
- Ardmore · 10 km
- Bala Cynwyd · 10 km
- Chester · 13 km
- Gloucester City · 13 km
Frost dates recorded at PHILADELPHIA INTL AP, 6 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.
BlissGarden. "When to Plant in Darby, PA — Frost Dates & Zone 7b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USW00013739. Retrieved from https://blissgarden.com/pennsylvania/darby.