What does USDA hardiness zone 5b mean in Indiana?

Zone 5b means an average annual extreme minimum winter temperature of −15 to −10 °F — the standard USDA measure of which perennials survive winter. 23 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 5b is the growing season longest?

Hamlet runs the longest season on this page at about 191 days; South Milford is shortest at about 159 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 5b?

Using Wheatfield's frost dates (this page's median-season location): start seeds indoors about Feb 28 – Mar 14, then transplant outside about May 2 – May 9. 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 5b 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 23 locations listed (see the table above for each location's own dates).

USDA zone 5b in Indiana

−15 to −10 °F avg. annual extreme minimum · 23 locations in this group · NOAA 1991–2020 normals

USDA plant hardiness zone 5b covers 23 locations across Indiana (average annual extreme minimum −15 to −10 °F): Arcola, IN, Buffalo, IN, Burket, IN, Crawfordsville, IN, Crown Point, IN, Fowler, IN, and 17 more. Average last spring frost across this group ranges April 19 (Hamlet) to May 2 (South Milford), and growing seasons run 159–191 days (South Milford to Hamlet) — 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 Wheatfield, this group's median-season location.

USDA zone: 5b−15 to −10 °F
Last frost range: Apr 19–May 2avg, 32°F
First frost range: Oct 10–Oct 27avg, 32°F
Growing season range: 159–191days

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.

Own frost dates per location.
Location	Also covers	Nearest station	Last frost	First frost	Season (days)
Arcola	—	Ft Wayne Intl Ap	Apr 24	Oct 21	178
Buffalo	Winamac, North Judson, Ora	Winamac 2sse	Apr 25	Oct 18	173
Burket	—	Warsaw	Apr 28	Oct 18	170
Crawfordsville	Waynetown, New Market, Alamo	Crawfordsville 6 Se	Apr 27	Oct 12	167
Crown Point	Cedar Lake, Lowell, Lake, DeMotte, Grant Park, Hebron, +5 more	Lowell	Apr 29	Oct 16	171
Fowler	Earl Park, Boswell	Boswell 4wnw	Apr 25	Oct 13	169
Groverton	—	Plymouth	Apr 25	Oct 21	178
Hamlet	Kingsford Heights	Laporte	Apr 19	Oct 27	191
Kennard	—	New Castle 3 Sw	Apr 27	Oct 17	173
Kentland	—	Kentland	Apr 23	Oct 14	175
Knox	—	Knox Wwtp	Apr 26	Oct 19	174
Mays	—	Rushville	Apr 19	Oct 23	185
Monon	Medaryville, Francesville	Francesville	Apr 26	Oct 17	173
Onward	—	Logansport Cicott St	Apr 20	Oct 23	185
Remington	Morocco, Goodland, Brook, Wolcott, Fair Oaks	Rensselaer	Apr 23	Oct 18	177
Saratoga	—	Winchester Airport 3 E	Apr 20	Oct 21	183
Servia	—	Wabash	Apr 23	Oct 21	181
South Milford	—	Garrett 1 S	May 2	Oct 10	159
State Line	—	Danville	Apr 21	Oct 20	181
Templeton	—	W Lafayette 6 Nw	Apr 26	Oct 12	169
Wanatah	Kouts, Hanna, San Pierre, La Crosse, Boone Grove, Wellsboro	Wanatah 2 Wnw	Apr 29	Oct 13	166
Waveland	—	Rockville	Apr 30	Oct 12	164
Wheatfield *	—	Wheatfield	Apr 25	Oct 17	173

* Wheatfield 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 (Wheatfield, representative)

Computed from Wheatfield's average frost dates — the median-season location in this Indianazone 5b 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).

Crop

JanFebMarAprMayJunJulAugSepOctNovDec

Tomato

Pepper

Cucumber

Summer squash / zucchini

Start indoors
Plant out
Fall sowing
First harvest

Planting windows for Wheatfield (Indiana, zone 5b), this group's representative location.
Crop	Frost tolerance	Start indoors	Plant out	First harvest	Fall planting	Season fit
Tomato	Tender	Feb 28 – Mar 14	May 2 – May 9	Jul 1 – Jul 21	—	matures comfortably
Pepper	Very tender	Feb 14 – Feb 28	May 9 – May 16	Jul 8 – Aug 7	—	matures comfortably
Cucumber	Tender	Mar 28 – Apr 4	May 2 – May 9	Jun 21 – Jul 11	—	matures comfortably
Summer squash / zucchini	Tender	—	May 2 – May 9	Jun 16 – Jul 1	—	matures comfortably
Bush bean	Tender	—	May 2 – May 9	Jun 21 – Jul 1	Aug 18 – Aug 28	matures comfortably
Sweet corn	Tender	—	Apr 25 – May 9	Jun 24 – Jul 24	—	matures comfortably
Basil	Very tender	Mar 14 – Mar 28	May 2 – May 9	Jun 1 – Jun 16	—	matures comfortably
Lettuce	Half-hardy	Mar 14 – Mar 28	Mar 28 – Apr 11	May 12 – May 27	Aug 4 – Aug 19	matures comfortably
Pea	Hardy	—	Mar 14 – Mar 28	May 8 – May 23	Jul 25 – Aug 9	matures comfortably
Spinach	Hardy	—	Mar 14 – Mar 28	Apr 23 – May 3	Aug 14 – Aug 24	matures comfortably
Carrot	Half-hardy	—	Apr 4 – Apr 11	Jun 3 – Jun 23	Jul 15 – Aug 4	matures comfortably
Broccoli	Half-hardy	Feb 28 – Mar 14	Mar 28 – Apr 11	May 22 – Jun 11	Jul 20 – Aug 9	matures comfortably

Which crops fit this growing season

Using Wheatfield's own 173-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 (Wheatfield)

From NOAA's 1991–2020 Climate Normals at station USC00129511. 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.

Freeze probabilities by temperature threshold (MM/DD, NOAA 1991–2020), Wheatfield.
Threshold	Last spring — avg	Last spring — 90%-safe	First fall — avg	First fall — 90%-safe	Season (days)
36°F	May 6	May 22	Oct 6	Oct 19	152
32°F (freeze)	Apr 25	May 11	Oct 17	Oct 29	173
28°F	Apr 15	Apr 29	Oct 28	Nov 9	194
24°F	Apr 4	Apr 18	Nov 6	Nov 21	217

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 23 locations is 3,113; Wheatfield's own reading is shown below.

Annual growing degree days for Wheatfield (°F·days, NOAA 1991–2020).
Model	°F·days	Used for
Base 50°F (warm-season)	3,119	standard warm-season base (tomato, corn, beans)
Base 40°F (cool-season)	5,294	cool-season crops (brassicas, greens)

Hardiness zone 5b in Indiana

Zone 5b means an average annual extreme minimum winter temperature of about −15 to −10 °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 zones6a, 6b, 7a.

Explore zone 5b in other states at zone 5b, or see all USDA hardiness zones.

Frequently asked questions

What does USDA hardiness zone 5b mean in Indiana?: Zone 5b means an average annual extreme minimum winter temperature of −15 to −10 °F — the standard USDA measure of which perennials survive winter. 23 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 5b is the growing season longest?: Hamlet runs the longest season on this page at about 191 days; South Milford is shortest at about 159 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 5b?: Using Wheatfield's frost dates (this page's median-season location): start seeds indoors about Feb 28 – Mar 14, then transplant outside about May 2 – May 9. 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 5b 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 23 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.