USDA zone 7a in Indiana
USDA plant hardiness zone 7a covers 10 locations across Indiana (average annual extreme minimum 0 to 5 °F): Boonville, IN, Charlestown, IN, Dale, IN, Evansville, IN, Evansville, IN, Fort Branch, IN, and 4 more. Average last spring frost across this group ranges March 29 (Evansville) to April 13 (Fort Branch), and growing seasons run 193–225 days (Charlestown to Evansville) — even within one state, because hardiness sets winter survival, not planting dates. The table below gives every Indiana location's own frost dates; the printable planting calendar uses Mount Vernon, this group's median-season location.
- USDA zone
- 7a0 to 5 °F
- Last frost range
- Mar 29–Apr 13avg, 32°F
- First frost range
- Oct 25–Nov 10avg, 32°F
- Growing season range
- 193–225days
Locations in this group
Every location below shares this zone and a nearby weather station, but keeps its own frost dates — find your town for its own numbers, or use the ZIP planner on the home page for an instant personalized answer.
| Location | Also covers | Nearest station | Last frost | First frost | Season (days) |
|---|---|---|---|---|---|
| Boonville | Sorgho, Chandler, Reo, Lynnville, Newburgh, Chrisney, +4 more | Boonville 1s | Apr 12 | Oct 25 | 196 |
| Charlestown | Pewee Valley, Goshen | Crestwood 4ne | Apr 12 | Oct 25 | 193 |
| Dale | Stendal, Holland, Somerville, Spurgeon | Stendal | Apr 6 | Oct 30 | 206 |
| Evansville | Henderson | Evansville Museum | Mar 29 | Nov 10 | 225 |
| Evansville | Darmstadt, Haubstadt, Elberfeld | Evansville Regional Ap | Apr 4 | Oct 29 | 206 |
| Fort Branch | Poseyville, Cynthiana, Somerville, Mackey | Princeton 1 W | Apr 13 | Oct 25 | 194 |
| Griffin | — | Grayville | Apr 7 | Oct 25 | 201 |
| Mount Vernon * | Blairsville, New Haven, Uniontown, New Harmony, Shawneetown | Mt Vernon | Apr 7 | Oct 28 | 202 |
| Santa Claus | Gentryville | Saint Meinrad | Apr 11 | Oct 26 | 197 |
| Santa Claus | Philpot, Thruston, Hawesville, Cloverport, Maceo, Cannelton, +5 more | Tell City | Apr 5 | Nov 1 | 208 |
* Mount Vernon is this group's median-season location — the calendar below is computed from its data.
Data: NOAA NCEI U.S. Climate Normals 1991–2020 (public domain) and USDA Plant Hardiness Zone Map 2023. Planting windows synthesized from U.S. Cooperative Extension guides.
Planting calendar (Mount Vernon, representative)
Computed from Mount Vernon's average frost dates — the median-season location in this Indianazone 7a group. hatched = start seeds indoors, solid green = plant out, teal = a fall sowing, and the terracotta dot marks the estimated first harvest. Ranges are extension-guide planning guidance, not guarantees — your own location's dates may run a week or two earlier or later (see the table above).
- Start indoors
- Plant out
- Fall sowing
- First harvest
| Crop | Frost tolerance | Start indoors | Plant out | First harvest | Fall planting | Season fit |
|---|---|---|---|---|---|---|
| Tomato | Tender | Feb 10 – Feb 24 | Apr 14 – Apr 21 | Jun 13 – Jul 3 | — | matures comfortably |
| Pepper | Very tender | Jan 27 – Feb 10 | Apr 21 – Apr 28 | Jun 20 – Jul 20 | — | matures comfortably |
| Cucumber | Tender | Mar 10 – Mar 17 | Apr 14 – Apr 21 | Jun 3 – Jun 23 | — | matures comfortably |
| Summer squash / zucchini | Tender | — | Apr 14 – Apr 21 | May 29 – Jun 13 | — | matures comfortably |
| Bush bean | Tender | — | Apr 14 – Apr 21 | Jun 3 – Jun 13 | Aug 29 – Sep 8 | matures comfortably |
| Sweet corn | Tender | — | Apr 7 – Apr 21 | Jun 6 – Jul 6 | — | matures comfortably |
| Basil | Very tender | Feb 24 – Mar 10 | Apr 14 – Apr 21 | May 14 – May 29 | — | matures comfortably |
| Lettuce | Half-hardy | Feb 24 – Mar 10 | Mar 10 – Mar 24 | Apr 24 – May 9 | Aug 15 – Aug 30 | matures comfortably |
| Pea | Hardy | — | Feb 24 – Mar 10 | Apr 20 – May 5 | Aug 5 – Aug 20 | matures comfortably |
| Spinach | Hardy | — | Feb 24 – Mar 10 | Apr 5 – Apr 15 | Aug 25 – Sep 4 | matures comfortably |
| Carrot | Half-hardy | — | Mar 17 – Mar 24 | May 16 – Jun 5 | Jul 26 – Aug 15 | matures comfortably |
| Broccoli | Half-hardy | Feb 10 – Feb 24 | Mar 10 – Mar 24 | May 4 – May 24 | Jul 31 – Aug 20 | matures comfortably |
Which crops fit this growing season
Using Mount Vernon's own 202-day growing season (32°F, NOAA 1991–2020 median) against each crop's real days-to-maturity range: 12 of 12 crops mature here with comfortable margin. A different location in the table above with a longer or shorter season will get a different mix — the ZIP planner on the home page gives your own.
Frost & freeze dates (Mount Vernon)
From NOAA's 1991–2020 Climate Normals at station USC00126001. The median (p50) is the average date; the 90%-safe column is the date the freeze has passed in about 9 years out of 10 — the conservative date to plant after or harvest before.
| Threshold | Last spring — avg | Last spring — 90%-safe | First fall — avg | First fall — 90%-safe | Season (days) |
|---|---|---|---|---|---|
| 36°F | Apr 21 | May 7 | Oct 17 | Oct 30 | 177 |
| 32°F (freeze) | Apr 7 | Apr 27 | Oct 28 | Nov 10 | 202 |
| 28°F | Mar 30 | Apr 14 | Nov 7 | Nov 25 | 224 |
| 24°F | Mar 17 | Apr 2 | Nov 20 | Dec 7 | 248 |
Growing degree days
Growing degree days (GDD) accumulate warmth above a base temperature over the year — a better predictor of crop development than the calendar alone. This group's median GDD (base 50°F) across all 10 locations is 4,150; Mount Vernon's own reading is shown below.
| Model | °F·days | Used for |
|---|---|---|
| Base 50°F (warm-season) | 4,094 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 6,625 | cool-season crops (brassicas, greens) |
Hardiness zone 7a in Indiana
Zone 7a means an average annual extreme minimum winter temperature of about 0 to 5 °F on the USDA's 2023 map — the number that tells you which perennials, shrubs, and trees reliably survive an average winter here. It does not set your planting dates, which come from the frost calendar above. Indiana spans 4 hardiness zones in this dataset — see all Indiana locations for the full range, including zones5b, 6a, 6b.
Explore zone 7a in other states at zone 7a, or see all USDA hardiness zones.
Frequently asked questions
- What does USDA hardiness zone 7a mean in Indiana?
- Zone 7a means an average annual extreme minimum winter temperature of 0 to 5 °F — the standard USDA measure of which perennials survive winter. 10 locations in Indiana fall in this zone. It does not set planting dates; see the frost calendar below for that.
- Where in Indiana's zone 7a is the growing season longest?
- Evansville runs the longest season on this page at about 225 days; Charlestown is shortest at about 193 days — they share the same hardiness zone, but they sit at different weather stations, so their frost calendars differ.
- When should I plant tomatoes in Indiana's zone 7a?
- Using Mount Vernon's frost dates (this page's median-season location): start seeds indoors about Feb 10 – Feb 24, then transplant outside about Apr 14 – Apr 21. Your own location in the table above may differ by a week or two — use the ZIP planner on the home page for your exact station's dates.
- Does every location in Indiana's zone 7a have the same frost dates?
- No — they do not all share a weather station, so frost dates vary by a week or more across the 10 locations listed (see the table above for each location's own dates).
Sources & method
Frost, freeze, growing-season, and growing-degree-day figures are NOAA NCEI U.S. Climate Normals 1991–2020, one reading per location's own nearest station (see the table above). The hardiness zone is the USDA Plant Hardiness Zone Map 2023, matched to each location's ZIP. Planting windows are computed by counting from the average last and first frost using per-crop offsets synthesized from U.S. Cooperative Extension guides — the full method and citations are on the methodology page.