Columbia, PA planting zone & frost dates
Columbia is in USDA hardiness zone 7a. The last spring frost usually comes around April 30 and the first fall frost around October 10, for a growing season of about 162 days.
Planting calendar for Columbia
Dates are counted from the average last spring frost (April 30) 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: Mar 5 – Mar 19 Transplant outdoors: May 7 – May 14 |
| Peppers | Start seeds indoors: Feb 19 – Mar 5 Transplant outdoors: May 14 – May 21 |
| Eggplant | Start seeds indoors: Feb 19 – Mar 5 Transplant outdoors: May 14 – May 21 |
| Broccoli | Start seeds indoors: Feb 19 – Mar 5 Transplant outdoors: Apr 2 – Apr 16 |
| Cabbage | Start seeds indoors: Feb 19 – Mar 5 Transplant outdoors: Apr 2 – Apr 16 |
| Onions (sets) | Plant outdoors: Apr 2 – Apr 16 |
| Peas | Sow outdoors: Mar 19 – Apr 2 |
| Spinach | Sow outdoors: Mar 19 – Apr 2 |
| Lettuce | Sow outdoors: Apr 2 – Apr 16 |
| Carrots | Sow outdoors: Apr 2 – Apr 16 |
| Potatoes | Plant outdoors: Apr 2 – Apr 16 |
| Beans | Sow outdoors: May 7 – May 14 |
| Sweet corn | Sow outdoors: May 7 – May 14 |
| Cucumbers | Sow outdoors: May 7 – May 14 |
| Squash & zucchini | Sow outdoors: May 7 – May 14 |
| Basil | Start seeds indoors: Mar 19 – Apr 2 Transplant outdoors: May 7 – May 14 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Aug 15 (8 weeks before the average first fall frost on Oct 10).
Useful for zone 7a 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
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Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Apr 16 | Apr 30 | May 13 |
| First 32°F frost in fall is before | Oct 26 | Oct 10 | Sep 29 |
How to read it: in spring there is a 10% chance of a frost after May 13, so that is a safe date for tender plants. In fall there is a 10% chance of frost before September 29. A hard freeze (28°F) usually ends around April 18.
Hardiness zone by ZIP code in Columbia
- 17512 zone 7a
Nearby cities
- Elizabethtown zone 7a, last frost Apr 9
- Lancaster zone 7a, last frost Apr 19
- York zone 7a, last frost Apr 26
- Hershey zone 7a, last frost Apr 9
- Shiloh zone 7a, last frost Apr 26
- Lebanon zone 7a, last frost Apr 20
- Weigelstown zone 7a, last frost Apr 27
- Ephrata zone 7a, last frost Apr 18
Questions
What growing zone is Columbia, PA?
Columbia is in USDA Plant Hardiness Zone 7a (average extreme winter low 0°F to 5°F), according to the USDA 2023 map.
When is the last frost in Columbia?
The average last spring frost (32°F) in Columbia is April 30. There is still a 10% chance of frost until May 13.
When can I plant tomatoes in Columbia?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around May 7 – May 14. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Landisville 2 Nw, PA (USC00364778), 11.6 km (7.2 mi) from the city center, elevation 110 m, based on 28 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.