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

Planting zone for 37023 — Big Rock, TN

ZIP code 37023 (Big Rock, Stewart County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is April 4 and the first fall frost October 31.

Where ZIP 37023 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.

Zone7a0 to 5 °F

Coldest night−17.8 to −15 °C

Last frostApr 4

First frostOct 31

2012 zone7a

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 7a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Big Rock, TN…

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 Big Rock, TN

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 4median — 50% chance of a later frost

Safe for tender plantsApril 21only 10% chance of frost after

First fall frostOctober 31median — 10% chance by Oct 18

Growing season210 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 23 and returns around November 11.

From the NOAA station Dover 1 W, TN — 9 miles away, elevation 476 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 37023

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 21 – Mar 7

SpinachSow outdoors · Feb 21 – Mar 14

Broccoli, cabbageStart indoors · Jan 24 – Feb 7

Broccoli, cabbageTransplant · Mar 14 – Mar 28

Onion setsPlant outdoors · Mar 7 – Mar 21

PotatoesPlant outdoors · Mar 14 – Mar 28

LettuceSow outdoors · Mar 7 – Mar 21

Carrots, beetsSow outdoors · Mar 14 – Mar 28

TomatoesStart indoors · Feb 7 – Feb 21

TomatoesTransplant · Apr 11 – Apr 25

Peppers, eggplantStart indoors · Jan 24 – Feb 7

Peppers, eggplantTransplant · Apr 18 – May 2

BeansSow outdoors · Apr 11 – Apr 25

Sweet cornSow outdoors · Apr 11 – Apr 25

Cucumbers, squashSow outdoors · Apr 11 – Apr 25

Fall lettuce, spinachSow outdoors · Sep 5 – Sep 19

GarlicPlant cloves · Oct 17 – Nov 21

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 4) and first fall frost (Oct 31) 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 37023 came on Feb 25 — 4 days earlier than the 1991–2020 average (Mar 1).

average
Mar 12026
Feb 25

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 7a in Tennessee

560 plants native to the lower 48 states, recorded in Tennessee, and rated by the USDA to survive 0 °F or colder — the bottom of zone 7a. 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 Big Rock, TN.

Soil in Big Rock, TN

The soil mapped at the center of ZIP 37023 is Hawthorne — slightly decomposed plant material, somewhat excessively drained.

TextureSlightly decomposed plant materialtop layer

pH4.4strongly acidic; most vegetables like 6.0–7.0

DrainageSomewhat excessively drainednatural drainage class

Organic matter50%high

Hydrologic groupBwater soaks in moderately

Farmland classNot prime farmlandUSDA classification

Map unit: Hawthorne gravelly silt loam, 12 to 20 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 37023; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Big Rock, TN

Summer high88 °Faverage high, July

Winter low27 °Faverage low, January

Hot days34days a year at 90 °F or more

Freezing nights79nights a year at 32 °F or less

Growing degree days4,553base 50 °F — the season’s usable heat

Longest day14 h 40 mindaylight on June 21

Shortest day9 h 39 mindaylight on December 21

Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully

Precipitation55.2 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: Dover 1 W, TN (9 mi away); precipitation: Dover 7.8 Nne, TN (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

5 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

370287b

Bumpus Mills, TN · 5 mi

422547a

La Fayette, KY · 9 mi

370587b

Dover, TN · 12 mi

370797b

Indian Mound, TN · 12 mi

Cumberland City, TN · 17 mi

Tennessee planting zones →

Questions about 37023

What planting zone is ZIP code 37023?

ZIP code 37023 (Big Rock, TN) is in USDA hardiness zone 7a on the 2023 map: the coldest night of an average winter reaches 0 to 5 °F (−17.8 to −15 °C).

When is the last frost in Big Rock, TN?

The median last spring frost (32 °F) near 37023 is April 4; after April 21 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Dover 1 W station.

When is the first frost in Big Rock, TN?

The median first fall frost near 37023 is October 31, giving a median frost-free growing season of 210 days.

When should I plant tomatoes in 37023?

Start tomato seeds indoors around Feb 7 – Feb 21 and set transplants outside around Apr 11 – Apr 25, one to three weeks after the median last frost.

How much rain and snow does 37023 get?

About 55.2 inches of precipitation a year (NOAA 1991–2020 normals, Dover 7.8 Nne station).

How hot do summers get in Big Rock, TN?

The average high peaks at 88 °F in July, with about 34 days a year at 90 °F or more.

What kind of soil does 37023 have?

The USDA soil survey maps Hawthorne at the center of ZIP 37023: slightly decomposed plant material, somewhat excessively drained, pH about 4.4 (strongly acidic).

Did spring come early in Big Rock, TN in 2026?

Spring leaf-out near 37023 came on Feb 25 in 2026, 4 days earlier than the 1991–2020 average (Mar 1), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Big Rock, TN?

Intermediate onions: the longest day near 37023 is 14 h 40 min, so day-neutral types bulb best; long-day varieties may not bulb fully.