Gardening in Indianapolis-Carmel-Greenwood, IN
This metro spans USDA zones 6a to 6b, so there is no single zone for Indianapolis-Carmel-Greenwood, IN and anyone who gives you one is rounding. 76% of its ZIP codes are zone 6a; the rest are not.
Which zone you are in depends where you are
Indianapolis-Carmel-Greenwood, IN covers 2 hardiness zones. A guide that gives the metro one zone has picked whichever is largest and rounded everyone else into it — which is fine for the 76% in zone 6a and wrong for the other 24%. Here is the actual split.
| Zone | ZIP codes | Share | |
|---|---|---|---|
| 6a | 91 | 76% | |
| 6b | 29 | 24% |
Zones are published per ZIP code, so yours is exact even though the metro's is not. The hardiness tool will tell you which one you are in.
Your freeze dates
Those are the earliest and latest medians among the 20 stations serving this metro — not an average, and not one station standing in for the rest. Half of years freeze later than a station's own median.
The spread is the point. Even in a metro that is one hardiness zone throughout, its stations disagree about the last spring freeze. Hardiness zone and frost date measure different things — a zone is the average annual coldest night, a freeze date is when the season turns — and a place can be uniform in one and varied in the other. Use the tools below with your own ZIP rather than the ends of this range.
Your growing season
NOAA publishes a growing-season length for each station, and across the 20 stations serving Indianapolis-Carmel-Greenwood, IN it runs 167–198 days . That figure is published, not computed from the two freeze dates — subtracting one from the other gives the wrong answer wherever a season crosses New Year. Mean summer high (June–August) runs 82–85 °F , below the 90 °F point where cool-season crops reliably bolt.
When to start seeds in Indianapolis-Carmel-Greenwood, IN
Every spring job for 63 crop dates, counted from this metro's own last spring freeze. Each is a range across all 20 stations — the earliest and latest that job falls anywhere in the metro — because no one station speaks for the whole area.
| Crop | Job | When | Offset |
|---|---|---|---|
| Green Onions | Start indoors | February 15 – March 2 | 8 weeks before |
| Peppers | Start indoors | February 15 – March 2 | 8 weeks before |
| Broccoli | Start indoors | March 1 – March 16 | 6 weeks before |
| Cabbage | Start indoors | March 1 – March 16 | 6 weeks before |
| Collards | Start indoors | March 1 – March 16 | 6 weeks before |
| Kale | Start indoors | March 1 – March 16 | 6 weeks before |
| Leaf Lettuce | Start indoors | March 1 – March 16 | 6 weeks before |
| Peas | Direct sow | March 1 – March 16 | 6 weeks before |
| Spinach | Direct sow | March 1 – March 16 | 6 weeks before |
| Sweet Potato | Start indoors | March 1 – March 16 | 6 weeks before |
| Tomatoes | Start indoors | March 1 – March 16 | 6 weeks before |
| Bok Choy | Start indoors | March 8 – March 23 | 5 weeks before |
| Kohlrabi | Start indoors | March 8 – March 23 | 5 weeks before |
| Swiss Chard | Start indoors | March 8 – March 23 | 5 weeks before |
| Arugula | Direct sow | March 15 – March 30 | 4 weeks before |
| Baby Salad Greens | Direct sow | March 15 – March 30 | 4 weeks before |
| Beets | Direct sow | March 15 – March 30 | 4 weeks before |
| Green Onions | Direct sow | March 15 – March 30 | 4 weeks before |
| Mustard Greens | Direct sow | March 15 – March 30 | 4 weeks before |
| Okra | Start indoors | March 15 – March 30 | 4 weeks before |
| Radishes | Direct sow | March 15 – March 30 | 4 weeks before |
| Turnips | Direct sow | March 15 – March 30 | 4 weeks before |
| Cabbage | Set out | March 22 – April 6 | 3 weeks before |
| Carrots | Direct sow | March 22 – April 6 | 3 weeks before |
| Collards | Direct sow | March 22 – April 6 | 3 weeks before |
| Collards | Set out | March 22 – April 6 | 3 weeks before |
| Cucumbers | Start indoors | March 22 – April 6 | 3 weeks before |
| Green Onions | Set out | March 22 – April 6 | 3 weeks before |
| Kale | Direct sow | March 22 – April 6 | 3 weeks before |
| Kale | Set out | March 22 – April 6 | 3 weeks before |
| Kohlrabi | Direct sow | March 22 – April 6 | 3 weeks before |
| Kohlrabi | Set out | March 22 – April 6 | 3 weeks before |
| Leaf Lettuce | Direct sow | March 22 – April 6 | 3 weeks before |
| Pumpkins | Start indoors | March 22 – April 6 | 3 weeks before |
| Summer Squash | Start indoors | March 22 – April 6 | 3 weeks before |
| Winter Squash | Start indoors | March 22 – April 6 | 3 weeks before |
| Zucchini | Start indoors | March 22 – April 6 | 3 weeks before |
| Bok Choy | Direct sow | March 29 – April 13 | 2 weeks before |
| Bok Choy | Set out | March 29 – April 13 | 2 weeks before |
| Broccoli | Set out | March 29 – April 13 | 2 weeks before |
| Cilantro | Direct sow | March 29 – April 13 | 2 weeks before |
| Leaf Lettuce | Set out | March 29 – April 13 | 2 weeks before |
| Swiss Chard | Direct sow | March 29 – April 13 | 2 weeks before |
| Swiss Chard | Set out | March 29 – April 13 | 2 weeks before |
| Dill | Direct sow | April 5 – April 20 | 1 week before |
| Bush Beans | Direct sow | April 19 – May 4 | 1 week after |
| Cucumbers | Set out | April 19 – May 4 | 1 week after |
| Pumpkins | Direct sow | April 19 – May 4 | 1 week after |
| Pumpkins | Set out | April 19 – May 4 | 1 week after |
| Summer Squash | Direct sow | April 19 – May 4 | 1 week after |
| Summer Squash | Set out | April 19 – May 4 | 1 week after |
| Sweet Corn | Direct sow | April 19 – May 4 | 1 week after |
| Tomatoes | Set out | April 19 – May 4 | 1 week after |
| Winter Squash | Direct sow | April 19 – May 4 | 1 week after |
| Winter Squash | Set out | April 19 – May 4 | 1 week after |
| Zucchini | Direct sow | April 19 – May 4 | 1 week after |
| Zucchini | Set out | April 19 – May 4 | 1 week after |
| Cucumbers | Direct sow | April 26 – May 11 | 2 weeks after |
| Okra | Direct sow | April 26 – May 11 | 2 weeks after |
| Okra | Set out | April 26 – May 11 | 2 weeks after |
| Peppers | Set out | April 26 – May 11 | 2 weeks after |
| Southern Peas | Direct sow | April 26 – May 11 | 2 weeks after |
| Sweet Potato | Set out | April 26 – May 11 | 2 weeks after |
The week offsets are conventional extension guidance and vary by variety; the freeze dates they are counted from are measured. For a single date rather than a range, run when do I start my seeds? with your own ZIP code.
What survives the winter changes across Indianapolis-Carmel-Greenwood, IN
Of 74 perennial fruits, nuts, berries, vegetables and herbs, 51 come through the winter in every zone this metro covers.
| Zone | ZIPs | Survive | Fail for being too warm |
|---|---|---|---|
| 6a | 91 | 51 of 74 | 0 |
| 6b | 29 | 51 of 74 | 0 |
The last column is the counterintuitive one, and it is why the totals do not simply rise as the winters get milder. Most temperate fruit needs a documented number of hours below about 45 °F to break dormancy and set a crop, so an apple fails in a winter that is too warm; currants and rhubarb cook in the summer heat that comes with it. See the full list with reasons.
The 20 stations behind these numbers
Every figure above comes from these, and each is named so you can check it. Distances vary by ZIP code, so the tools report yours rather than this page guessing.
| Station | NOAA ID | Last spring freeze | First fall freeze | Season |
|---|---|---|---|---|
| Anderson Sewage Plt, IN | USC00120177 | April 19 | October 23 | 186 days |
| Bloomington Indiana Univ, IN | USC00120784 | April 15 | October 26 | 192 days |
| Carmel 3 E, IN | USC00121303 | April 21 | October 21 | 183 days |
| Castleton 2 S, IN | USC00121326 | April 18 | October 26 | 190 days |
| Crawfordsville 6 SE, IN | USC00121873 | April 27 | October 12 | 167 days |
| Elwood, IN | USC00122638 | April 24 | October 18 | 175 days |
| Franklin WWTP, IN | USC00123091 | April 20 | October 19 | 180 days |
| Greencastle 1 W, IN | USC00123513 | April 27 | October 15 | 169 days |
| Greenfield, IN | USC00123527 | April 19 | October 22 | 185 days |
| Indianapolis Eagle Creek AP, IN | USW00053842 | April 12 | October 29 | 198 days |
| Indianapolis Nwfo, IN | USC00124260 | April 12 | October 27 | 196 days |
| Indianapolis SE Side, IN | USC00124272 | April 20 | October 21 | 183 days |
| Indianapolis, IN | USW00093819 | April 15 | October 26 | 193 days |
| Jamestown 2 E, IN | USC00124356 | April 23 | October 19 | 178 days |
| Kokomo 3 Wsw, IN | USC00124662 | April 27 | October 18 | 174 days |
| Martinsville 2 SW, IN | USC00125407 | April 24 | October 15 | 173 days |
| Shelbyville Muni AP, IN | USW00053866 | April 14 | October 23 | 191 days |
| Shelbyville Sewage Plt, IN | USC00127999 | April 17 | October 22 | 187 days |
| Tipton 5 SW, IN | USC00128784 | April 23 | October 17 | 174 days |
| Whitestown, IN | USC00129557 | April 21 | October 20 | 180 days |
These are medians, not averages — NOAA publishes freeze dates as a probability distribution, and half of years freeze later than the date shown.
Work out your own dates
Each of these takes a ZIP code and answers for that ZIP alone, citing the station it used and how far away it is. There is a ZIP box in the header of every page.
- What survives my winter?
Runs on the hardiness zone, so it answers for all of Indianapolis-Carmel-Greenwood, IN at once — zone across 74 perennial fruits, berries, vegetables and herbs.
- When do I start my seeds?
Dates every spring job from your own last freeze — sow indoors, set out, direct sow.
- When do I sow the next round?
How often each crop is worth re-sowing, and when the next sowing is due.
- What can I still plant?
Counts the growing days left before your first fall freeze, crop by crop.
Where these numbers come from
The hardiness zone is the USDA 2023 Plant Hardiness Zone Map, published per ZIP code by PRISM at Oregon State. The freeze dates are NOAA's 1991–2020 Climate Normals, read from every station whose normals cover a ZIP code in this metro. Nothing here is estimated, and no station stands in for another.
This page names no single station on purpose. Picking one to represent a metro sounds reasonable and is not: the station serving the most ZIP codes is an artifact of where ZIP centroids happen to fall, and it selects a lock on the Monongahela for Pittsburgh and a far southern suburb for Chicago. A range across every station is true; a single cited date for a whole metro is not.