USDA zone 6b in Indiana
USDA plant hardiness zone 6b covers 38 locations across Indiana (average annual extreme minimum −5 to 0 °F): Bedford, IN, Bloomington, IN, Bright, IN, Brownstown, IN, Edinburgh, IN, Elnora, IN, and 32 more. Average last spring frost across this group ranges March 31 (Floyds Knobs) to April 30 (Milan), and growing seasons run 168–225 days (Milan to Georgetown) — 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 Needham, this group's median-season location.
- USDA zone
- 6b−5 to 0 °F
- Last frost range
- Mar 31–Apr 30avg, 32°F
- First frost range
- Oct 15–Nov 9avg, 32°F
- Growing season range
- 168–225days
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) |
|---|---|---|---|---|---|
| Bedford | Harrodsburg, Mitchell, Avoca, Owensburg, Williams, Judah, +3 more | Oolitic Purdue Ex Fm | Apr 20 | Oct 20 | 181 |
| Bloomington | Smithville-Sanders, Ellettsville, Nashville | Bloomington Indiana Univ | Apr 15 | Oct 26 | 192 |
| Bright | Batesville, Sunman, Morris, New Trenton, Hamburg, Mount Carmel | Brookville | Apr 20 | Oct 21 | 182 |
| Brownstown | Crothersville, Cortland, Freetown, Medora | Seymour 2 N | Apr 16 | Oct 21 | 187 |
| Edinburgh | Geneva | Shelbyville Sewage Plt | Apr 17 | Oct 22 | 187 |
| Elnora | Odon, Newberry | Elnora | Apr 9 | Oct 25 | 197 |
| Ferdinand | St. Meinrad, Leopold | Saint Meinrad | Apr 11 | Oct 26 | 197 |
| Floyds Knobs | Lanesville | Louisville Intl Ap | Mar 31 | Nov 7 | 222 |
| Franklin | — | Franklin Wwtp | Apr 20 | Oct 19 | 180 |
| Freelandville | Carlisle, Westphalia, Sandborn | Freelandville | Apr 9 | Oct 30 | 202 |
| French Lick | Dubois, Eckerty, Schnellville, Birdseye, Taswell, St. Anthony, +1 more | Dubois S In Forage Fm | Apr 25 | Oct 15 | 172 |
| Georgetown | New Salisbury, Greenville, Crandall | Louisville Mcalpine | Mar 31 | Nov 9 | 225 |
| Greensburg | New Point, St. Paul, Napoleon | Greensburg | Apr 15 | Oct 26 | 194 |
| Helmsburg | Morgantown | Martinsville 2 Sw | Apr 24 | Oct 15 | 173 |
| Huntingburg | Winslow, Velpen | Stendal | Apr 6 | Oct 30 | 206 |
| Indianapolis | — | Indianapolis Se Side | Apr 20 | Oct 21 | 183 |
| Indianapolis | — | Carmel 3 E | Apr 21 | Oct 21 | 183 |
| Indianapolis | Greenwood | Indianapolis | Apr 15 | Oct 26 | 193 |
| Indianapolis | — | Indianapolis Eagle Creek Ap | Apr 12 | Oct 29 | 198 |
| Jasper | Shoals, Otwell, Loogootee, Huron, Alfordsville | Shoals 8 S | Apr 15 | Oct 23 | 189 |
| Leopold | — | Tell City | Apr 5 | Nov 1 | 208 |
| Linton | Sullivan, Lyons, Worthington, Farmersburg, Dugger, Paxton, +3 more | Shakamak Sp | Apr 14 | Oct 26 | 193 |
| Madison | New Washington, Hanover, Carrollton, Milton, Cross Plains, Bedford, +1 more | Madison Sewage Plt | Apr 11 | Oct 31 | 201 |
| Milan | Moores Hill | Milan 5 Ne | Apr 30 | Oct 16 | 168 |
| Needham * | — | Shelbyville Muni Ap | Apr 14 | Oct 23 | 191 |
| North Vernon | Holton, Westport, Scipio, Dupont, Paris Crossing, Commiskey, +3 more | N Vernon 2 Ese | Apr 21 | Oct 21 | 180 |
| Owensburg | — | Crane Nsa | Apr 9 | Oct 31 | 202 |
| Paoli | Hardinsburg, Orleans, Milltown, Marengo, Campbellsburg, Prospect | Paoli | Apr 21 | Oct 18 | 178 |
| Petersburg | — | Petersburg 61 Brg | Apr 20 | Oct 22 | 186 |
| Prairieton | — | Terre Haute Hulman Rgnl Ap | Apr 16 | Oct 18 | 183 |
| Princeton | Johnson, Patoka, Francisco, Hazleton | Princeton 1 W | Apr 13 | Oct 25 | 194 |
| Ramsey | Grantsburg, Depauw, Alton | English | Apr 17 | Oct 19 | 184 |
| Salem | New Pekin, Borden, Palmyra, Fredericksburg, Vallonia | Salem | Apr 17 | Oct 22 | 186 |
| Scottsburg | Austin, Henryville, Underwood, Otisco | Scottsburg | Apr 18 | Oct 20 | 185 |
| Stanford | Solsberry, Hashtown | Bloomington Monroe Co Ap | Apr 17 | Oct 22 | 185 |
| Taylorsville | Newbern, Hope, Grandview Lake, Elizabethtown, Grammer, Petersville, +1 more | Columbus | Apr 11 | Oct 25 | 195 |
| Vincennes | Bicknell, Bruceville, Oaktown, Monroe | Vincennes 5 Ne | Apr 11 | Oct 26 | 197 |
| Washington | Montgomery, Wheatland, Plainville | Washington 1 W | Apr 10 | Oct 25 | 197 |
* Needham 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 (Needham, representative)
Computed from Needham's average frost dates — the median-season location in this Indianazone 6b 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 17 – Mar 3 | Apr 21 – Apr 28 | Jun 20 – Jul 10 | — | matures comfortably |
| Pepper | Very tender | Feb 3 – Feb 17 | Apr 28 – May 5 | Jun 27 – Jul 27 | — | matures comfortably |
| Cucumber | Tender | Mar 17 – Mar 24 | Apr 21 – Apr 28 | Jun 10 – Jun 30 | — | matures comfortably |
| Summer squash / zucchini | Tender | — | Apr 21 – Apr 28 | Jun 5 – Jun 20 | — | matures comfortably |
| Bush bean | Tender | — | Apr 21 – Apr 28 | Jun 10 – Jun 20 | Aug 24 – Sep 3 | matures comfortably |
| Sweet corn | Tender | — | Apr 14 – Apr 28 | Jun 13 – Jul 13 | — | matures comfortably |
| Basil | Very tender | Mar 3 – Mar 17 | Apr 21 – Apr 28 | May 21 – Jun 5 | — | matures comfortably |
| Lettuce | Half-hardy | Mar 3 – Mar 17 | Mar 17 – Mar 31 | May 1 – May 16 | Aug 10 – Aug 25 | matures comfortably |
| Pea | Hardy | — | Mar 3 – Mar 17 | Apr 27 – May 12 | Jul 31 – Aug 15 | matures comfortably |
| Spinach | Hardy | — | Mar 3 – Mar 17 | Apr 12 – Apr 22 | Aug 20 – Aug 30 | matures comfortably |
| Carrot | Half-hardy | — | Mar 24 – Mar 31 | May 23 – Jun 12 | Jul 21 – Aug 10 | matures comfortably |
| Broccoli | Half-hardy | Feb 17 – Mar 3 | Mar 17 – Mar 31 | May 11 – May 31 | Jul 26 – Aug 15 | matures comfortably |
Which crops fit this growing season
Using Needham's own 191-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 (Needham)
From NOAA's 1991–2020 Climate Normals at station USW00053866. 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 24 | May 8 | Oct 13 | Oct 24 | 170 |
| 32°F (freeze) | Apr 14 | Apr 29 | Oct 23 | Nov 4 | 191 |
| 28°F | Apr 1 | Apr 16 | Nov 3 | Nov 19 | 216 |
| 24°F | Mar 21 | Apr 5 | Nov 15 | Dec 5 | 242 |
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 38 locations is 3,754; Needham's own reading is shown below.
| Model | °F·days | Used for |
|---|---|---|
| Base 50°F (warm-season) | 3,784 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 6,216 | cool-season crops (brassicas, greens) |
Hardiness zone 6b in Indiana
Zone 6b means an average annual extreme minimum winter temperature of about −5 to 0 °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, 7a.
Explore zone 6b in other states at zone 6b, or see all USDA hardiness zones.
Frequently asked questions
- What does USDA hardiness zone 6b mean in Indiana?
- Zone 6b means an average annual extreme minimum winter temperature of −5 to 0 °F — the standard USDA measure of which perennials survive winter. 38 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 6b is the growing season longest?
- Georgetown runs the longest season on this page at about 225 days; Milan is shortest at about 168 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 6b?
- Using Needham's frost dates (this page's median-season location): start seeds indoors about Feb 17 – Mar 3, then transplant outside about Apr 21 – Apr 28. 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 6b 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 38 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.