Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated

Planting zone for 46759 — Keystone, IN

ZIP code 46759 (Keystone, Wells County) is in USDA zone 6a: the coldest winter night averages −10 to −5 °F. The median last spring frost is April 22 and the first fall frost October 22.

Where ZIP 46759 is

Outlined: the ZIP code area · tap the map for the zone at any spot · scroll or pinch to zoom

Not the official USDA Plant Hardiness Zone Map. Zones come from the 2023 USDA hardiness-zone data by the PRISM Group, Oregon State University; we re-mapped and recolored them. The official map is at planthardiness.ars.usda.gov.

Zone6a−10 to −5 °F
Coldest night−23.3 to −20.6 °C
Last frostApr 22
First frostOct 22
2012 zone6a

Same zone as on the 2012 map. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 6a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Keystone, IN…

Forecast data: National Weather Service (api.weather.gov), public domain. This is not a warning service — for official frost and freeze warnings see weather.gov.

Frost dates in Keystone, IN

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 22median — 50% chance of a later frost
Safe for tender plantsMay 7only 10% chance of frost after
First fall frostOctober 22median — 10% chance by Oct 7
Growing season181 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 10 and returns around November 1.

From the NOAA station Hartford City 4 Ese, IN — 13 miles away, elevation 925 ft. NOAA NCEI U.S. Climate Normals 1991–2020, 32 °F threshold. Low spots and valleys can freeze later in spring than the station.

When to plant vegetables in 46759

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 11 – Mar 25
SpinachSow outdoors · Mar 11 – Apr 1
Broccoli, cabbageStart indoors · Feb 11 – Feb 25
Broccoli, cabbageTransplant · Apr 1 – Apr 15
Onion setsPlant outdoors · Mar 25 – Apr 8
PotatoesPlant outdoors · Apr 1 – Apr 15
LettuceSow outdoors · Mar 25 – Apr 8
Carrots, beetsSow outdoors · Apr 1 – Apr 15
TomatoesStart indoors · Feb 25 – Mar 11
TomatoesTransplant · Apr 29 – May 13
Peppers, eggplantStart indoors · Feb 11 – Feb 25
Peppers, eggplantTransplant · May 6 – May 20
BeansSow outdoors · Apr 29 – May 13
Sweet cornSow outdoors · Apr 29 – May 13
Cucumbers, squashSow outdoors · Apr 29 – May 13
Fall lettuce, spinachSow outdoors · Aug 27 – Sep 10
GarlicPlant cloves · Oct 8 – Nov 12
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 22) and first fall frost (Oct 22) with the rules of thumb U.S. extension services publish. Cool-season crops take a light frost; warm-season crops do best once the soil is above about 60 °F.

When spring arrived in 2026

In 2026, spring leaf-out near 46759 came on Mar 12 — 19 days earlier than the 1991–2020 average (Mar 31).

JanFebMarAprMayJun

The Spring Index marks the day when accumulated warmth is enough for lilac and honeysuckle to leaf out — a widely used signal that the growing season has started. Source: USA National Phenology Network, www.usanpn.org — Spring Indices, first leaf, 2026 (data as of 2026-09-08) and 30-year average 1991–2020 (CC BY 4.0).

Native plants for zone 6a in Indiana

558 plants native to the lower 48 states, recorded in Indiana, and rated by the USDA to survive −10 °F or colder — the bottom of zone 6a. Each links to its USDA PLANTS profile.

Trees 71

American basswood100 ft · blooms late spring · low shade tolerance · to −46 °FAmerican beech80 ft · blooms mid spring · low shade tolerance · to −44 °FAmerican chestnut115 ft · blooms early summer · high shade tolerance · to −33 °FAmerican elm120 ft · blooms early spring · medium shade tolerance · to −46 °FAmerican sycamore100 ft · blooms spring · medium shade tolerance · to −34 °Farborvitae50 ft · blooms mid spring · medium shade tolerance · to −33 °F

Shrubs 105

alderleaf buckthorn3 ft · blooms late spring · low shade tolerance · to −33 °FAllegheny serviceberry35 ft · blooms early spring · low shade tolerance · to −38 °Falternateleaf dogwood25 ft · blooms mid spring · low shade tolerance · to −47 °FAmerican black currant3 ft · blooms early spring · to −46 °FAmerican hazelnut10 ft · blooms spring · medium shade tolerance · to −33 °FAmerican holly40 ft · blooms mid spring · low shade tolerance · to −20 °F

Wildflowers & perennials 200

American bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °FAmerican licorice4 ft · blooms late spring · medium shade tolerance · to −38 °FAmerican lotus3 ft · blooms mid summer · high shade tolerance · to −36 °FAmerican pokeweed7 ft · blooms mid summer · low shade tolerance · to −33 °FAmerican speedwell0.8 ft · blooms mid summer · low shade tolerance · to −38 °F

Grasses 161

American beachgrass2.5 ft · blooms spring · high shade tolerance · to −28 °Farctic brome3 ft · blooms early summer · low shade tolerance · to −33 °Fawlfruit sedge4 ft · blooms mid spring · low shade tolerance · to −38 °Fbeaked spikerush3 ft · blooms late spring · high shade tolerance · to −28 °FBebb's sedge3 ft · blooms late spring · low shade tolerance · to −38 °FBicknell's sedge3 ft · blooms late spring · low shade tolerance · to −38 °F

Vines 9

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °Fcatbird grape30 ft · blooms late spring · medium shade tolerance · to −13 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Ffrost grape83 ft · blooms late spring · medium shade tolerance · to −23 °Friverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °Fsummer grape30 ft · blooms late spring · low shade tolerance · to −23 °F

Source: USDA, NRCS. 2026. The PLANTS Database (plants.usda.gov), National Plant Data Team — state distribution, native status and the “Temperature, Minimum” characteristic. Check light, moisture and soil needs before buying; local nurseries and your state native plant society can confirm what thrives in Keystone, IN.

Soil in Keystone, IN

The soil mapped at the center of ZIP 46759 is Del Rey — silt loam, somewhat poorly drained.

TextureSilt loama good balance for most vegetables
pH6.5neutral; most vegetables like 6.0–7.0
DrainageSomewhat poorly drainedconsider raised beds
Organic matter2.5%moderate
Hydrologic groupC/Dslow when drained; wet otherwise
Farmland classPrime farmland if drainedUSDA classification

Map unit: Del Rey-Blount silt loams, 0 to 1 percent slopes.

Soil Survey Staff, Natural Resources Conservation Service, USDA. Soil Survey Geographic (SSURGO) Database, via Soil Data Access, accessed 2026-10-29. The soil at the center point of ZIP 46759; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Keystone, IN

Summer high83 °Faverage high, July
Winter low19 °Faverage low, January
Hot days13days a year at 90 °F or more
Freezing nights117nights a year at 32 °F or less
Growing degree days3,290base 50 °F — the season’s usable heat
Longest day15 h 05 mindaylight on June 21
Shortest day9 h 16 mindaylight on December 21
Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)
Precipitation41.6 inper year, rain and melted snow

Average high and low, by month

10°20°30°40°50°60°70°80°90°32 °FJanuary: average high 33 °F, low 19 °F 33°19° JanFebruary: average high 37 °F, low 21 °F 37°21° FebMarch: average high 48 °F, low 30 °F 48°30° MarApril: average high 61 °F, low 41 °F 61°41° AprMay: average high 72 °F, low 52 °F 72°52° MayJune: average high 80 °F, low 61 °F 80°61° JunJuly: average high 83 °F, low 64 °F 83°64° JulAugust: average high 82 °F, low 62 °F 82°62° AugSeptember: average high 76 °F, low 55 °F 76°55° SepOctober: average high 64 °F, low 44 °F 64°44° OctNovember: average high 50 °F, low 34 °F 50°34° NovDecember: average high 38 °F, low 25 °F 38°25° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 2.75 in precipitation 2.8 JanFebruary: 2.29 in precipitation 2.3 FebMarch: 2.84 in precipitation 2.8 MarApril: 3.95 in precipitation 4.0 AprMay: 4.60 in precipitation 4.6 MayJune: 4.76 in precipitation 4.8 JunJuly: 4.73 in precipitation 4.7 JulAugust: 3.83 in precipitation 3.8 AugSeptember: 3.18 in precipitation 3.2 SepOctober: 2.93 in precipitation 2.9 OctNovember: 3.15 in precipitation 3.1 NovDecember: 2.59 in precipitation 2.6 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Hartford City 4 Ese, IN (13 mi away); precipitation: Bluffton 0.9 Se, IN (9 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6a.

467786a
Petroleum, IN · <1 mi
467816a
Poneto, IN · 5 mi
473596a
Montpelier, IN · 7 mi
473696a
Pennville, IN · 7 mi
467696a
Linn Grove, IN · 8 mi
467146a
Bluffton, IN · 8 mi
467666a
Liberty Center, IN · 9 mi
467406a
Geneva, IN · 11 mi

Indiana planting zones →

Questions about 46759

What planting zone is ZIP code 46759?

ZIP code 46759 (Keystone, IN) is in USDA hardiness zone 6a on the 2023 map: the coldest night of an average winter reaches −10 to −5 °F (−23.3 to −20.6 °C).

When is the last frost in Keystone, IN?

The median last spring frost (32 °F) near 46759 is April 22; after May 7 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Hartford City 4 Ese station.

When is the first frost in Keystone, IN?

The median first fall frost near 46759 is October 22, giving a median frost-free growing season of 181 days.

When should I plant tomatoes in 46759?

Start tomato seeds indoors around Feb 25 – Mar 11 and set transplants outside around Apr 29 – May 13, one to three weeks after the median last frost.

How much rain and snow does 46759 get?

About 41.6 inches of precipitation a year (NOAA 1991–2020 normals, Bluffton 0.9 Se station).

How hot do summers get in Keystone, IN?

The average high peaks at 83 °F in July, with about 13 days a year at 90 °F or more.

What kind of soil does 46759 have?

The USDA soil survey maps Del Rey at the center of ZIP 46759: silt loam, somewhat poorly drained, pH about 6.5 (neutral).

Did spring come early in Keystone, IN in 2026?

Spring leaf-out near 46759 came on Mar 12 in 2026, 19 days earlier than the 1991–2020 average (Mar 31), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Keystone, IN?

Long-day onions: the longest day near 46759 is 15 h 05 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).