Greencastle, IN planting zone & frost dates
Greencastle is in USDA hardiness zone 6a. The last spring frost usually comes around April 27 and the first fall frost around October 15, for a growing season of about 169 days.
Planting calendar for Greencastle
Dates are counted from the average last spring frost (April 27) 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 2 – Mar 16 Transplant outdoors: May 4 – May 11 |
| Peppers | Start seeds indoors: Feb 16 – Mar 2 Transplant outdoors: May 11 – May 18 |
| Eggplant | Start seeds indoors: Feb 16 – Mar 2 Transplant outdoors: May 11 – May 18 |
| Broccoli | Start seeds indoors: Feb 16 – Mar 2 Transplant outdoors: Mar 30 – Apr 13 |
| Cabbage | Start seeds indoors: Feb 16 – Mar 2 Transplant outdoors: Mar 30 – Apr 13 |
| Onions (sets) | Plant outdoors: Mar 30 – Apr 13 |
| Peas | Sow outdoors: Mar 16 – Mar 30 |
| Spinach | Sow outdoors: Mar 16 – Mar 30 |
| Lettuce | Sow outdoors: Mar 30 – Apr 13 |
| Carrots | Sow outdoors: Mar 30 – Apr 13 |
| Potatoes | Plant outdoors: Mar 30 – Apr 13 |
| Beans | Sow outdoors: May 4 – May 11 |
| Sweet corn | Sow outdoors: May 4 – May 11 |
| Cucumbers | Sow outdoors: May 4 – May 11 |
| Squash & zucchini | Sow outdoors: May 4 – May 11 |
| Basil | Start seeds indoors: Mar 16 – Mar 30 Transplant outdoors: May 4 – May 11 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Aug 20 (8 weeks before the average first fall frost on Oct 15).
Useful for zone 6a 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 13 | Apr 27 | May 15 |
| First 32°F frost in fall is before | Oct 26 | Oct 15 | Oct 1 |
How to read it: in spring there is a 10% chance of a frost after May 15, 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 15.
Hardiness zone by ZIP code in Greencastle
- 46135 zone 6a
Nearby cities
- Crawfordsville zone 5b, last frost Apr 27
- Plainfield zone 6a, last frost Apr 12
- Avon zone 6a, last frost Apr 12
- Martinsville zone 6a, last frost Apr 24
- Brownsburg zone 6a, last frost Apr 12
- Fairfield Heights zone 6a, last frost Apr 12
- Lebanon zone 6a, last frost Apr 21
- Terre Haute zone 6a, last frost Apr 15
Questions
What growing zone is Greencastle, IN?
Greencastle is in USDA Plant Hardiness Zone 6a (average extreme winter low -10°F to -5°F), according to the USDA 2023 map.
When is the last frost in Greencastle?
The average last spring frost (32°F) in Greencastle is April 27. There is still a 10% chance of frost until May 15.
When can I plant tomatoes in Greencastle?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around May 4 – May 11. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Greencastle 1 W, IN (USC00123513), 1.0 km (0.6 mi) from the city center, elevation 224 m, based on 21 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.