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

Planting zone for 44621 — Dennison, OH

ZIP code 44621 (Dennison, Tuscarawas County) is in USDA zone 6b: the coldest winter night averages −5 to 0 °F. The median last spring frost is April 29 and the first fall frost October 15.

Where ZIP 44621 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 29

First frostOct 15

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 Dennison, 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 Dennison, OH

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 29median — 50% chance of a later frost

Safe for tender plantsMay 17only 10% chance of frost after

First fall frostOctober 15median — 10% chance by Oct 2

Growing season170 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 17 and returns around October 28.

From the NOAA station Dennison Wtr Wks, OH — 4 miles away, elevation 860 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 44621

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 18 – Apr 1

SpinachSow outdoors · Mar 18 – Apr 8

Broccoli, cabbageStart indoors · Feb 18 – Mar 4

Broccoli, cabbageTransplant · Apr 8 – Apr 22

Onion setsPlant outdoors · Apr 1 – Apr 15

PotatoesPlant outdoors · Apr 8 – Apr 22

LettuceSow outdoors · Apr 1 – Apr 15

Carrots, beetsSow outdoors · Apr 8 – Apr 22

TomatoesStart indoors · Mar 4 – Mar 18

TomatoesTransplant · May 6 – May 20

Peppers, eggplantStart indoors · Feb 18 – Mar 4

Peppers, eggplantTransplant · May 13 – May 27

BeansSow outdoors · May 6 – May 20

Sweet cornSow outdoors · May 6 – May 20

Cucumbers, squashSow outdoors · May 6 – May 20

Fall lettuce, spinachSow outdoors · Aug 20 – Sep 3

GarlicPlant cloves · Oct 1 – Nov 5

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 29) and first fall frost (Oct 15) 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 44621 came on Mar 11 — 17 days earlier than the 1991–2020 average (Mar 28).

average
Mar 282026
Mar 11

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.

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 Dennison, OH.

Soil in Dennison, OH

The soil mapped at the center of ZIP 44621 is Bethesda — loam, well drained.

TextureLoama good balance for most vegetables

pH4.8strongly acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter0.92%low — add compost

Hydrologic groupDwater soaks in very slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Bethesda loam, 25 to 70 percent slopes, reclaimed.

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 44621; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Dennison, OH

Summer high85 °Faverage high, July

Winter low20 °Faverage low, January

Hot days22days a year at 90 °F or more

Freezing nights139nights a year at 32 °F or less

Growing degree days3,075base 50 °F — the season’s usable heat

Longest day15 h 04 mindaylight on June 21

Shortest day9 h 17 mindaylight on December 21

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

Precipitation42.4 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: Dennison Wtr Wks, OH (4 mi away); precipitation: Dennison Wtr Wks, OH (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 6b.

Uhrichsville, OH · 5 mi

446756b

Sherrodsville, OH · 5 mi

446956b

Bowerston, OH · 6 mi

446826b

Tuscarawas, OH · 7 mi

446796b

Stillwater, OH · 8 mi

446636b

New Philadelphia, OH · 9 mi

Ohio planting zones →

Questions about 44621

What planting zone is ZIP code 44621?

ZIP code 44621 (Dennison, 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 Dennison, OH?

The median last spring frost (32 °F) near 44621 is April 29; after May 17 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Dennison Wtr Wks station.

When is the first frost in Dennison, OH?

The median first fall frost near 44621 is October 15, giving a median frost-free growing season of 170 days.

When should I plant tomatoes in 44621?

Start tomato seeds indoors around Mar 4 – Mar 18 and set transplants outside around May 6 – May 20, one to three weeks after the median last frost.

How much rain and snow does 44621 get?

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

How hot do summers get in Dennison, OH?

The average high peaks at 85 °F in July, with about 22 days a year at 90 °F or more.

What kind of soil does 44621 have?

The USDA soil survey maps Bethesda at the center of ZIP 44621: loam, well drained, pH about 4.8 (strongly acidic).

Did spring come early in Dennison, OH in 2026?

Spring leaf-out near 44621 came on Mar 11 in 2026, 17 days earlier than the 1991–2020 average (Mar 28), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Dennison, OH?

Long-day onions: the longest day near 44621 is 15 h 04 min, so summer days reach 15+ hours, enough for long-day varieties (intermediate types work too).

Did the zone for 44621 change?

Yes. The 2012 USDA map put 44621 in zone 6a; the 2023 map puts it in zone 6b. The newer map uses 1991–2020 data and more weather stations.