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

Planting zone for 45812 — Alger, OH

ZIP code 45812 (Alger, Hardin 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 24.

Where ZIP 45812 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 24

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 Alger, 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 Alger, OH

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 24median — 10% chance by Oct 9

Growing season182 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 10 and returns around November 3.

From the NOAA station Kenton, OH — 11 miles away, elevation 997 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 45812

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 29 – Sep 12

GarlicPlant cloves · Oct 10 – Nov 14

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 22) and first fall frost (Oct 24) 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 45812 came on Mar 12 — 20 days earlier than the 1991–2020 average (Apr 1).

average
Apr 12026
Mar 12

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 Alger, OH.

Soil in Alger, OH

The soil mapped at the center of ZIP 45812 is Roundhead — muck, very poorly drained.

TextureMucktop layer

pH6.5neutral; most vegetables like 6.0–7.0

DrainageVery poorly drainedconsider raised beds

Organic matter37.5%high

Hydrologic groupC/Dslow when drained; wet otherwise

Farmland classPrime farmland if drainedUSDA classification

Map unit: Roundhead muck.

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 45812; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Alger, OH

Summer high84 °Faverage high, July

Winter low18 °Faverage low, January

Hot days16days a year at 90 °F or more

Freezing nights124nights a year at 32 °F or less

Growing degree days3,219base 50 °F — the season’s usable heat

Longest day15 h 05 mindaylight on June 21

Shortest day9 h 15 mindaylight on December 21

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

Precipitation38.5 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: Kenton, OH (11 mi away); precipitation: Ada 5.4 Ne, OH (10 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6a.

Waynesfield, OH · 8 mi

458546a

Lafayette, OH · 9 mi

433106a

Belle Center, OH · 10 mi

Ohio planting zones →

Questions about 45812

What planting zone is ZIP code 45812?

ZIP code 45812 (Alger, OH) 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 Alger, OH?

The median last spring frost (32 °F) near 45812 is April 22; after May 7 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Kenton station.

When is the first frost in Alger, OH?

The median first fall frost near 45812 is October 24, giving a median frost-free growing season of 182 days.

When should I plant tomatoes in 45812?

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 45812 get?

About 38.5 inches of precipitation a year (NOAA 1991–2020 normals, Ada 5.4 Ne station).

How hot do summers get in Alger, OH?

The average high peaks at 84 °F in July, with about 16 days a year at 90 °F or more.

What kind of soil does 45812 have?

The USDA soil survey maps Roundhead at the center of ZIP 45812: muck, very poorly drained, pH about 6.5 (neutral).

Did spring come early in Alger, OH in 2026?

Spring leaf-out near 45812 came on Mar 12 in 2026, 20 days earlier than the 1991–2020 average (Apr 1), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Alger, OH?

Long-day onions: the longest day near 45812 is 15 h 05 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).