Indianapolis, IN planting zone & frost dates
Indianapolis is in USDA hardiness zone 6b. The last spring frost usually comes around April 20 and the first fall frost around October 21, for a growing season of about 183 days.
Planting calendar for Indianapolis
Dates are counted from the average last spring frost (April 20) 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 23 – Mar 9 Transplant outdoors: Apr 27 – May 4 |
| Peppers | Start seeds indoors: Feb 9 – Feb 23 Transplant outdoors: May 4 – May 11 |
| Eggplant | Start seeds indoors: Feb 9 – Feb 23 Transplant outdoors: May 4 – May 11 |
| Broccoli | Start seeds indoors: Feb 9 – Feb 23 Transplant outdoors: Mar 23 – Apr 6 |
| Cabbage | Start seeds indoors: Feb 9 – Feb 23 Transplant outdoors: Mar 23 – Apr 6 |
| Onions (sets) | Plant outdoors: Mar 23 – Apr 6 |
| Peas | Sow outdoors: Mar 9 – Mar 23 |
| Spinach | Sow outdoors: Mar 9 – Mar 23 |
| Lettuce | Sow outdoors: Mar 23 – Apr 6 |
| Carrots | Sow outdoors: Mar 23 – Apr 6 |
| Potatoes | Plant outdoors: Mar 23 – Apr 6 |
| Beans | Sow outdoors: Apr 27 – May 4 |
| Sweet corn | Sow outdoors: Apr 27 – May 4 |
| Cucumbers | Sow outdoors: Apr 27 – May 4 |
| Squash & zucchini | Sow outdoors: Apr 27 – May 4 |
| Basil | Start seeds indoors: Mar 9 – Mar 23 Transplant outdoors: Apr 27 – May 4 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Aug 26 (8 weeks before the average first fall frost on Oct 21).
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 6 | Apr 20 | May 5 |
| First 32°F frost in fall is before | Nov 3 | Oct 21 | Oct 7 |
How to read it: in spring there is a 10% chance of a frost after May 5, so that is a safe date for tender plants. In fall there is a 10% chance of frost before October 7. A hard freeze (28°F) usually ends around April 7.
Hardiness zone by ZIP code in Indianapolis
- 46201 zone 6b
- 46202 zone 6b
- 46203 zone 6b
- 46204 zone 6b
- 46205 zone 6b
- 46206 zone 6b
- 46207 zone 6b
- 46208 zone 6b
- 46209 zone 6b
- 46213 zone 6b
- 46214 zone 6b
- 46216 zone 6a
- 46217 zone 6b
- 46218 zone 6a
- 46219 zone 6a
- 46220 zone 6b
- 46221 zone 6b
- 46222 zone 6b
- 46224 zone 6b
- 46225 zone 6b
- 46226 zone 6a
- 46227 zone 6b
- 46228 zone 6b
- 46229 zone 6a
- 46230 zone 6b
- 46231 zone 6b
- 46234 zone 6a
- 46235 zone 6a
- 46236 zone 6a
- 46237 zone 6a
- 46239 zone 6a
- 46240 zone 6b
- 46241 zone 6b
- 46242 zone 6b
- 46244 zone 6b
- 46247 zone 6b
- 46249 zone 6a
- 46250 zone 6a
- 46251 zone 6b
- 46253 zone 6b
- 46254 zone 6b
- 46255 zone 6b
- 46256 zone 6a
- 46259 zone 6a
- 46260 zone 6a
- 46262 zone 6b
- 46268 zone 6a
- 46277 zone 6b
- 46278 zone 6a
- 46280 zone 6a
- 46282 zone 6b
- 46283 zone 6b
- 46285 zone 6b
- 46288 zone 6b
- 46290 zone 6a
- 46298 zone 6a
Nearby cities
- Beech Grove zone 6b, last frost Apr 20
- Broad Ripple zone 6b, last frost Apr 18
- Speedway zone 6b, last frost Apr 12
- Lawrence zone 6a, last frost Apr 18
- Greenwood zone 6a, last frost Apr 20
- Zionsville zone 6a, last frost Apr 21
- Carmel zone 6a, last frost Apr 21
- Fairfield Heights zone 6a, last frost Apr 12
Questions
What growing zone is Indianapolis, IN?
Indianapolis is in USDA Plant Hardiness Zone 6b (average extreme winter low -5°F to 0°F), according to the USDA 2023 map. Some ZIP codes of the city fall in zone 6a.
When is the last frost in Indianapolis?
The average last spring frost (32°F) in Indianapolis is April 20. There is still a 10% chance of frost until May 5.
When can I plant tomatoes in Indianapolis?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around Apr 27 – May 4. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station Indianapolis Se Side, IN (USC00124272), 9.6 km (6.0 mi) from the city center, elevation 258 m, based on 23 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.