Darby, PA planting zone & frost dates
Darby is in USDA hardiness zone 7b. The last spring frost usually comes around April 2 and the first fall frost around November 10, for a growing season of about 224 days.
Planting calendar for Darby
Dates are counted from the average last spring frost (April 2) using the typical timing recommended by U.S. extension services. Warm-season crops go out only after the danger of frost has passed and the soil has warmed.
| Crop | When |
|---|---|
| Tomatoes | Start seeds indoors: Feb 5 – Feb 19 Transplant outdoors: Apr 9 – Apr 16 |
| Peppers | Start seeds indoors: Jan 22 – Feb 5 Transplant outdoors: Apr 16 – Apr 23 |
| Eggplant | Start seeds indoors: Jan 22 – Feb 5 Transplant outdoors: Apr 16 – Apr 23 |
| Broccoli | Start seeds indoors: Jan 22 – Feb 5 Transplant outdoors: Mar 5 – Mar 19 |
| Cabbage | Start seeds indoors: Jan 22 – Feb 5 Transplant outdoors: Mar 5 – Mar 19 |
| Onions (sets) | Plant outdoors: Mar 5 – Mar 19 |
| Peas | Sow outdoors: Feb 19 – Mar 5 |
| Spinach | Sow outdoors: Feb 19 – Mar 5 |
| Lettuce | Sow outdoors: Mar 5 – Mar 19 |
| Carrots | Sow outdoors: Mar 5 – Mar 19 |
| Potatoes | Plant outdoors: Mar 5 – Mar 19 |
| Beans | Sow outdoors: Apr 9 – Apr 16 |
| Sweet corn | Sow outdoors: Apr 9 – Apr 16 |
| Cucumbers | Sow outdoors: Apr 9 – Apr 16 |
| Squash & zucchini | Sow outdoors: Apr 9 – Apr 16 |
| Basil | Start seeds indoors: Feb 19 – Mar 5 Transplant outdoors: Apr 9 – Apr 16 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Sep 15 (8 weeks before the average first fall frost on Nov 10).
Useful for zone 7b gardens
- Seed starting kit with dome — to start seeds indoors before the last frost
- LED grow light for seedlings — stops leggy seedlings
- Frost cloth / plant covers — for late spring and early fall frosts
- Soil thermometer — warm-season crops need soil above 60°F
As an Amazon Associate, FrostZoneMap earns from qualifying purchases, at no extra cost to you.
Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Mar 19 | Apr 2 | Apr 13 |
| First 32°F frost in fall is before | Nov 24 | Nov 10 | Oct 30 |
How to read it: in spring there is a 10% chance of a frost after April 13, so that is a safe date for tender plants. In fall there is a 10% chance of frost before October 30. A hard freeze (28°F) usually ends around March 22.
Hardiness zone by ZIP code in Darby
- 19023 zone 7b
Nearby cities
- Yeadon zone 7b, last frost Mar 30
- Lansdowne zone 7b, last frost Apr 2
- Drexel Hill zone 7b, last frost Apr 2
- Springfield zone 7b, last frost Apr 2
- Havertown zone 7b, last frost Mar 30
- Ardmore zone 7b, last frost Mar 30
- Philadelphia zone 7b, last frost Mar 30
- Broomall zone 7b, last frost Apr 8
Questions
What growing zone is Darby, PA?
Darby is in USDA Plant Hardiness Zone 7b (average extreme winter low 5°F to 10°F), according to the USDA 2023 map.
When is the last frost in Darby?
The average last spring frost (32°F) in Darby is April 2. There is still a 10% chance of frost until April 13.
When can I plant tomatoes in Darby?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Apr 9 – Apr 16. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Philadelphia Intl Ap, PA (USW00013739), 6.1 km (3.8 mi) from the city center, elevation 3 m, based on 30 years of records. Hardiness zone: USDA Plant Hardiness Zone Map 2023 for the ZIP code nearest to the city center. Microclimates (valleys, hills, cities, coasts) can be warmer or colder: check the local forecast before planting. How we calculate the data.