Indiana, PA planting zone & frost dates
Indiana is in USDA hardiness zone 6b. The last spring frost usually comes around May 8 and the first fall frost around October 13, for a growing season of about 157 days.
Planting calendar for Indiana
Dates are counted from the average last spring frost (May 8) 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 13 – Mar 27 Transplant outdoors: May 15 – May 22 |
| Peppers | Start seeds indoors: Feb 27 – Mar 13 Transplant outdoors: May 22 – May 29 |
| Eggplant | Start seeds indoors: Feb 27 – Mar 13 Transplant outdoors: May 22 – May 29 |
| Broccoli | Start seeds indoors: Feb 27 – Mar 13 Transplant outdoors: Apr 10 – Apr 24 |
| Cabbage | Start seeds indoors: Feb 27 – Mar 13 Transplant outdoors: Apr 10 – Apr 24 |
| Onions (sets) | Plant outdoors: Apr 10 – Apr 24 |
| Peas | Sow outdoors: Mar 27 – Apr 10 |
| Spinach | Sow outdoors: Mar 27 – Apr 10 |
| Lettuce | Sow outdoors: Apr 10 – Apr 24 |
| Carrots | Sow outdoors: Apr 10 – Apr 24 |
| Potatoes | Plant outdoors: Apr 10 – Apr 24 |
| Beans | Sow outdoors: May 15 – May 22 |
| Sweet corn | Sow outdoors: May 15 – May 22 |
| Cucumbers | Sow outdoors: May 15 – May 22 |
| Squash & zucchini | Sow outdoors: May 15 – May 22 |
| Basil | Start seeds indoors: Mar 27 – Apr 10 Transplant outdoors: May 15 – May 22 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Aug 18 (8 weeks before the average first fall frost on Oct 13).
Useful for zone 6b 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
- Cold frame / mini greenhouse — adds weeks to a short season
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Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Apr 23 | May 8 | May 24 |
| First 32°F frost in fall is before | Oct 27 | Oct 13 | Oct 1 |
How to read it: in spring there is a 10% chance of a frost after May 24, so that is a safe date for tender plants. In fall there is a 10% chance of frost before October 1. A hard freeze (28°F) usually ends around April 27.
Hardiness zone by ZIP code in Indiana
- 15701 zone 6b
- 15705 zone 6b
Nearby cities
- Johnstown zone 6b, last frost May 17
- Greensburg zone 6b, last frost May 1
- Natrona Heights zone 6b, last frost Apr 16
- Murrysville zone 6b, last frost Apr 22
- Lower Burrell zone 6b, last frost Apr 16
- Plum zone 6b, last frost Apr 16
- New Kensington zone 6b, last frost Apr 16
- Monroeville zone 6b, last frost Apr 22
Questions
What growing zone is Indiana, PA?
Indiana is in USDA Plant Hardiness Zone 6b (average extreme winter low -5°F to 0°F), according to the USDA 2023 map.
When is the last frost in Indiana?
The average last spring frost (32°F) in Indiana is May 8. There is still a 10% chance of frost until May 24.
When can I plant tomatoes in Indiana?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around May 15 – May 22. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Indiana 3 Se, PA (USC00364214), 3.9 km (2.4 mi) from the city center, elevation 336 m, based on 27 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.