Data: 2023 USDA zones (PRISM/OSU) · NOAA 1991–2020 normals · updated Oct 29, 2026

Planting zone for Troy, OH

Troy, OH is in USDA zone 6a across its 2 ZIP codes. The median last spring frost is April 18 and the first fall frost October 23.

Troy on the zone map

Outlined: its 1 ZIP code areas · 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

ZIP codes2

Last frostApr 18

First frostOct 23

Growing season186 days

6a 2 ZIPs

Frost forecast — next 7 nights

live from the National Weather Service

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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 Troy, OH

JanFebMarAprMayJunJulAugSepOctNovDec

Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free

Last spring frostApril 18median — 50% chance of a later frost

Safe for tender plantsMay 5only 10% chance of frost after

First fall frostOctober 23median — 10% chance by Oct 9

Growing season186 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 5 and returns around November 3.

From the NOAA station Piqua Wwtp, OH, elevation 853 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 Troy

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 7 – Mar 21

SpinachSow outdoors · Mar 7 – Mar 28

Broccoli, cabbageStart indoors · Feb 7 – Feb 21

Broccoli, cabbageTransplant · Mar 28 – Apr 11

Onion setsPlant outdoors · Mar 21 – Apr 4

PotatoesPlant outdoors · Mar 28 – Apr 11

LettuceSow outdoors · Mar 21 – Apr 4

Carrots, beetsSow outdoors · Mar 28 – Apr 11

TomatoesStart indoors · Feb 21 – Mar 7

TomatoesTransplant · Apr 25 – May 9

Peppers, eggplantStart indoors · Feb 7 – Feb 21

Peppers, eggplantTransplant · May 2 – May 16

BeansSow outdoors · Apr 25 – May 9

Sweet cornSow outdoors · Apr 25 – May 9

Cucumbers, squashSow outdoors · Apr 25 – May 9

Fall lettuce, spinachSow outdoors · Aug 28 – Sep 11

GarlicPlant cloves · Oct 9 – Nov 13

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 18) and first fall frost (Oct 23) 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 45374 came on Mar 10 — 16 days earlier than the 1991–2020 average (Mar 26).

average
Mar 262026
Mar 10

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 Ohio

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

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 Troy, OH.

Soil in Troy, OH

The soil mapped at the center of ZIP 45374 is Crosby — silt loam, somewhat poorly drained.

TextureSilt loama good balance for most vegetables

pH6.2slightly acidic; most vegetables like 6.0–7.0

DrainageSomewhat poorly drainedconsider raised beds

Organic matter2.5%moderate

Hydrologic groupC/Dslow when drained; wet otherwise

Farmland classNot prime farmlandUSDA classification

Map unit: Crosby, Southern Ohio Till Plain-Urban land complex, 0 to 2 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 45374; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Troy, OH

Summer high84 °Faverage high, July

Winter low21 °Faverage low, January

Hot days17days a year at 90 °F or more

Freezing nights111nights a year at 32 °F or less

Growing degree days3,450base 50 °F — the season’s usable heat

Longest day15 h 01 mindaylight on June 21

Shortest day9 h 19 mindaylight on December 21

Onions to growLong-daysummer days reach 15+ hours, enough for long-day varieties (intermediate types work too)

Precipitation40.7 inper year, rain and melted snow

Average high and low, by month

Precipitation by month inches

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Piqua Wwtp, OH (6 mi away); precipitation: Piqua Wwtp, OH (6 mi away). Daylight is calculated from latitude.

ZIP codes in Troy

Ohio planting zones →

Questions about Troy

What planting zone is Troy, OH?

Troy, OH is in USDA hardiness zone 6a on the 2023 map (6a: −10 to −5 °F).

When is the last frost in Troy, OH?

The median last spring frost is April 18 and the median first fall frost is October 23 (NOAA 1991–2020 normals, Piqua Wwtp station).

When can I plant a garden in Troy, OH?

Cool-season crops like peas and spinach go in around Mar 7 – Mar 28; tomatoes, peppers, beans and squash after about Apr 25, once frost risk has passed.

What kind of onions grow in Troy, OH?

Long-day onions: the longest day is 15 h 01 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

How much rain and snow does Troy, OH get?

About 40.7 inches of precipitation a year (NOAA 1991–2020 normals).