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

Planting zone for 45146 — Martinsville, OH

ZIP code 45146 (Martinsville, Clinton County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 19 and the first fall frost October 22.

Where ZIP 45146 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.

Zone6b−5 to 0 °F
Coldest night−20.6 to −17.8 °C
Last frostApr 19
First frostOct 22
2012 zone6a

Was 6a on the 2012 map — half a zone warmer now. The zone is the one at the center of the ZIP code; hilly ZIPs can span two zones. What zone 6b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Martinsville, OH…

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 Martinsville, OH

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 19median — 50% chance of a later frost
Safe for tender plantsMay 6only 10% chance of frost after
First fall frostOctober 22median — 10% chance by Oct 8
Growing season185 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 6 and returns around November 1.

From the NOAA station Cincinnati, OH — 7 miles away, elevation 1,056 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 45146

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 8 – Mar 22
SpinachSow outdoors · Mar 8 – Mar 29
Broccoli, cabbageStart indoors · Feb 8 – Feb 22
Broccoli, cabbageTransplant · Mar 29 – Apr 12
Onion setsPlant outdoors · Mar 22 – Apr 5
PotatoesPlant outdoors · Mar 29 – Apr 12
LettuceSow outdoors · Mar 22 – Apr 5
Carrots, beetsSow outdoors · Mar 29 – Apr 12
TomatoesStart indoors · Feb 22 – Mar 8
TomatoesTransplant · Apr 26 – May 10
Peppers, eggplantStart indoors · Feb 8 – Feb 22
Peppers, eggplantTransplant · May 3 – May 17
BeansSow outdoors · Apr 26 – May 10
Sweet cornSow outdoors · Apr 26 – May 10
Cucumbers, squashSow outdoors · Apr 26 – May 10
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 19) 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 45146 came on Mar 10 — 14 days earlier than the 1991–2020 average (Mar 24).

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 6b in Ohio

570 plants native to the lower 48 states, recorded in Ohio, and rated by the USDA to survive −5 °F or colder — the bottom of zone 6b. 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 109

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 203

American bur-reed3 ft · blooms indeterminate · medium shade tolerance · to −33 °FAmerican eelgrass1 ft · blooms mid summer · high shade tolerance · to −33 °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 °FAmerican vetch1.3 ft · blooms late spring · high shade tolerance · to −38 °F

Grasses 165

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 10

American bittersweet15 ft · blooms spring · low shade tolerance · to −38 °Fdevil's darning needles15 ft · blooms mid summer · medium shade tolerance · to −38 °Ffrost grape83 ft · blooms late spring · medium shade tolerance · to −23 °Fgraybark grape50 ft · blooms late spring · medium shade tolerance · to −8 °Fheartleaf peppervine2 ft · blooms late spring · low shade tolerance · to −8 °Friverbank grape45 ft · blooms late spring · medium shade tolerance · to −33 °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 Martinsville, OH.

Soil in Martinsville, OH

The soil mapped at the center of ZIP 45146 is Xenia — silt loam, moderately well drained.

TextureSilt loama good balance for most vegetables
pH6.5neutral; most vegetables like 6.0–7.0
DrainageModerately well drainednatural drainage class
Organic matter1.5%low — add compost
Hydrologic groupC/Dslow when drained; wet otherwise
Farmland classprime farmlandUSDA classification

Map unit: Xenia silt loam, Southern Ohio Till Plain, 2 to 6 percent slopes, eroded.

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 45146; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Martinsville, OH

Summer high84 °Faverage high, July
Winter low21 °Faverage low, January
Hot days14days a year at 90 °F or more
Freezing nights110nights a year at 32 °F or less
Growing degree days3,368base 50 °F — the season’s usable heat
Longest day14 h 56 mindaylight on June 21
Shortest day9 h 24 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation42.4 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 37 °F, low 21 °F 37°21° JanFebruary: average high 41 °F, low 24 °F 41°24° FebMarch: average high 51 °F, low 32 °F 51°32° MarApril: average high 64 °F, low 42 °F 64°42° AprMay: average high 73 °F, low 52 °F 73°52° MayJune: average high 82 °F, low 60 °F 82°60° JunJuly: average high 84 °F, low 63 °F 84°63° JulAugust: average high 83 °F, low 61 °F 83°61° AugSeptember: average high 77 °F, low 54 °F 77°54° SepOctober: average high 65 °F, low 44 °F 65°44° OctNovember: average high 52 °F, low 34 °F 52°34° NovDecember: average high 41 °F, low 27 °F 41°27° Dec

Precipitation by month inches

0″1″2″3″4″5″January: 2.91 in precipitation 2.9 JanFebruary: 2.73 in precipitation 2.7 FebMarch: 3.63 in precipitation 3.6 MarApril: 4.46 in precipitation 4.5 AprMay: 4.63 in precipitation 4.6 MayJune: 4.64 in precipitation 4.6 JunJuly: 3.88 in precipitation 3.9 JulAugust: 3.16 in precipitation 3.2 AugSeptember: 2.93 in precipitation 2.9 SepOctober: 3.20 in precipitation 3.2 OctNovember: 3.05 in precipitation 3.0 NovDecember: 3.18 in precipitation 3.2 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Cincinnati, OH (7 mi away); precipitation: Cincinnati, OH (7 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6b.

451146b
Cuba, OH · 4 mi
451486b
Midland, OH · 5 mi
451596b
New Vienna, OH · 6 mi
451426b
Lynchburg, OH · 7 mi
451076b
Blanchester, OH · 9 mi
451776b
Wilmington, OH · 10 mi
451326b
Highland, OH · 11 mi
451136b
Clarksville, OH · 11 mi

Ohio planting zones →

Questions about 45146

What planting zone is ZIP code 45146?

ZIP code 45146 (Martinsville, OH) is in USDA hardiness zone 6b on the 2023 map: the coldest night of an average winter reaches −5 to 0 °F (−20.6 to −17.8 °C).

When is the last frost in Martinsville, OH?

The median last spring frost (32 °F) near 45146 is April 19; after May 6 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Cincinnati station.

When is the first frost in Martinsville, OH?

The median first fall frost near 45146 is October 22, giving a median frost-free growing season of 185 days.

When should I plant tomatoes in 45146?

Start tomato seeds indoors around Feb 22 – Mar 8 and set transplants outside around Apr 26 – May 10, one to three weeks after the median last frost.

How much rain and snow does 45146 get?

About 42.4 inches of precipitation a year (NOAA 1991–2020 normals, Cincinnati station).

How hot do summers get in Martinsville, OH?

The average high peaks at 84 °F in July, with about 14 days a year at 90 °F or more.

What kind of soil does 45146 have?

The USDA soil survey maps Xenia at the center of ZIP 45146: silt loam, moderately well drained, pH about 6.5 (neutral).

Did spring come early in Martinsville, OH in 2026?

Spring leaf-out near 45146 came on Mar 10 in 2026, 14 days earlier than the 1991–2020 average (Mar 24), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Martinsville, OH?

Intermediate onions: the longest day near 45146 is 14 h 56 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 45146 change?

Yes. The 2012 USDA map put 45146 in zone 6a; the 2023 map puts it in zone 6b. The newer map uses 1991–2020 data and more weather stations.