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

Planting zone for 37397 — Whitwell, TN

ZIP code 37397 (Whitwell, Marion County) is in USDA zone 7b: the coldest winter night averages 5 to 10 °F. The median last spring frost is March 26 and the first fall frost November 8.

Where ZIP 37397 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.

Zone7b5 to 10 °F

Coldest night−15 to −12.2 °C

Last frostMar 26

First frostNov 8

2012 zone7b

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 7b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Whitwell, 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 Whitwell, TN

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMarch 26median — 50% chance of a later frost

Safe for tender plantsApril 13only 10% chance of frost after

First fall frostNovember 8median — 10% chance by Oct 25

Growing season228 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 12 and returns around November 24.

From the NOAA station Whitwell-Sequatchie Vly, TN — 6 miles away, elevation 1,020 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 37397

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 12 – Feb 26

SpinachSow outdoors · Feb 12 – Mar 5

Broccoli, cabbageStart indoors · Jan 15 – Jan 29

Broccoli, cabbageTransplant · Mar 5 – Mar 19

Onion setsPlant outdoors · Feb 26 – Mar 12

PotatoesPlant outdoors · Mar 5 – Mar 19

LettuceSow outdoors · Feb 26 – Mar 12

Carrots, beetsSow outdoors · Mar 5 – Mar 19

TomatoesStart indoors · Jan 29 – Feb 12

TomatoesTransplant · Apr 2 – Apr 16

Peppers, eggplantStart indoors · Jan 15 – Jan 29

Peppers, eggplantTransplant · Apr 9 – Apr 23

BeansSow outdoors · Apr 2 – Apr 16

Sweet cornSow outdoors · Apr 2 – Apr 16

Cucumbers, squashSow outdoors · Apr 2 – Apr 16

Fall lettuce, spinachSow outdoors · Sep 13 – Sep 27

GarlicPlant cloves · Oct 25 – Nov 29

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 26) and first fall frost (Nov 8) 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 37397 came on Feb 20 — about the same time as the 1991–2020 average (Feb 18).

average
Feb 182026
Feb 20

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 7b in Tennessee

566 plants native to the lower 48 states, recorded in Tennessee, and rated by the USDA to survive 5 °F or colder — the bottom of zone 7b. 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 Whitwell, TN.

Soil in Whitwell, TN

The soil mapped at the center of ZIP 37397 is Pope — loam, well drained.

TextureLoama good balance for most vegetables

pH4.6strongly acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter2.5%moderate

Hydrologic groupBwater soaks in moderately

Farmland classprime farmlandUSDA classification

Map unit: Barbourville loam (Pope).

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 37397; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Whitwell, TN

Summer high88 °Faverage high, July

Winter low32 °Faverage low, January

Hot days32days a year at 90 °F or more

Freezing nights63nights a year at 32 °F or less

Growing degree days4,762base 50 °F — the season’s usable heat

Longest day14 h 32 mindaylight on June 21

Shortest day9 h 47 mindaylight on December 21

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

Precipitation61.9 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: Whitwell-Sequatchie Vly, TN (6 mi away); precipitation: Whitwell 0.3 Se, TN (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

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

373747b

Sequatchie, TN · 9 mi

373777b

Signal Mountain, TN · 9 mi

374057b

Chattanooga, TN · 9 mi

Chattanooga, TN · 12 mi

373877a

Tracy City, TN · 12 mi

373407b

Guild, TN · 13 mi

Tennessee planting zones →

Questions about 37397

What planting zone is ZIP code 37397?

ZIP code 37397 (Whitwell, TN) is in USDA hardiness zone 7b on the 2023 map: the coldest night of an average winter reaches 5 to 10 °F (−15 to −12.2 °C).

When is the last frost in Whitwell, TN?

The median last spring frost (32 °F) near 37397 is March 26; after April 13 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Whitwell-Sequatchie Vly station.

When is the first frost in Whitwell, TN?

The median first fall frost near 37397 is November 8, giving a median frost-free growing season of 228 days.

When should I plant tomatoes in 37397?

Start tomato seeds indoors around Jan 29 – Feb 12 and set transplants outside around Apr 2 – Apr 16, one to three weeks after the median last frost.

How much rain and snow does 37397 get?

About 61.9 inches of precipitation a year (NOAA 1991–2020 normals, Whitwell 0.3 Se station).

How hot do summers get in Whitwell, TN?

The average high peaks at 88 °F in July, with about 32 days a year at 90 °F or more.

What kind of soil does 37397 have?

The USDA soil survey maps Pope at the center of ZIP 37397: loam, well drained, pH about 4.6 (strongly acidic).

Did spring come early in Whitwell, TN in 2026?

Spring leaf-out near 37397 came on Feb 20 in 2026, about the same as the 1991–2020 average (Feb 18), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Whitwell, TN?

Intermediate onions: the longest day near 37397 is 14 h 32 min, so day-neutral types bulb best; long-day varieties may not bulb fully.