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

Planting zone for 37391 — Turtletown, TN

ZIP code 37391 (Turtletown, Polk County) is in USDA zone 7b: the coldest winter night averages 5 to 10 °F. The median last spring frost is April 13 and the first fall frost October 24.

Where ZIP 37391 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 frostApr 13

First frostOct 24

2012 zone7a

Was 7a 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 7b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Turtletown, 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 Turtletown, TN

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 13median — 50% chance of a later frost

Safe for tender plantsApril 29only 10% chance of frost after

First fall frostOctober 24median — 10% chance by Oct 10

Growing season193 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 31 and returns around November 2.

From the NOAA station Tellico Plains, TN — 19 miles away, elevation 909 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 37391

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 2 – Mar 16

SpinachSow outdoors · Mar 2 – Mar 23

Broccoli, cabbageStart indoors · Feb 2 – Feb 16

Broccoli, cabbageTransplant · Mar 23 – Apr 6

Onion setsPlant outdoors · Mar 16 – Mar 30

PotatoesPlant outdoors · Mar 23 – Apr 6

LettuceSow outdoors · Mar 16 – Mar 30

Carrots, beetsSow outdoors · Mar 23 – Apr 6

TomatoesStart indoors · Feb 16 – Mar 2

TomatoesTransplant · Apr 20 – May 4

Peppers, eggplantStart indoors · Feb 2 – Feb 16

Peppers, eggplantTransplant · Apr 27 – May 11

BeansSow outdoors · Apr 20 – May 4

Sweet cornSow outdoors · Apr 20 – May 4

Cucumbers, squashSow outdoors · Apr 20 – May 4

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 13) 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 37391 came on Feb 21 — 3 days earlier than the 1991–2020 average (Feb 24).

average
Feb 242026
Feb 21

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 Turtletown, TN.

Soil in Turtletown, TN

The soil mapped at the center of ZIP 37391 is Junaluska — moderately decomposed plant material, well drained.

TextureModerately decomposed plant materialtop layer

pH4.2strongly acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter60%high

Hydrologic groupCwater soaks in slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Junaluska-Tsali complex, 35 to 65 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 37391; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Turtletown, TN

Summer high90 °Faverage high, July

Winter low28 °Faverage low, January

Hot days55days a year at 90 °F or more

Freezing nights87nights a year at 32 °F or less

Growing degree days4,545base 50 °F — the season’s usable heat

Longest day14 h 31 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

Precipitation58.4 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: Tellico Plains, TN (19 mi away); precipitation: Murphy 15.5 Wnw, NC (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 7b.

Copperhill, TN · 7 mi

305557b

Mc Caysville, GA · 9 mi

373697b

Reliance, TN · 10 mi

305597b

Mineral Bluff, GA · 10 mi

373147b

Cokercreek, TN · 11 mi

289067b

Murphy, NC · 12 mi

Tennessee planting zones →

Questions about 37391

What planting zone is ZIP code 37391?

ZIP code 37391 (Turtletown, 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 Turtletown, TN?

The median last spring frost (32 °F) near 37391 is April 13; after April 29 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Tellico Plains station.

When is the first frost in Turtletown, TN?

The median first fall frost near 37391 is October 24, giving a median frost-free growing season of 193 days.

When should I plant tomatoes in 37391?

Start tomato seeds indoors around Feb 16 – Mar 2 and set transplants outside around Apr 20 – May 4, one to three weeks after the median last frost.

How much rain and snow does 37391 get?

About 58.4 inches of precipitation a year (NOAA 1991–2020 normals, Murphy 15.5 Wnw station).

How hot do summers get in Turtletown, TN?

The average high peaks at 90 °F in July, with about 55 days a year at 90 °F or more.

What kind of soil does 37391 have?

The USDA soil survey maps Junaluska at the center of ZIP 37391: moderately decomposed plant material, well drained, pH about 4.2 (strongly acidic).

Did spring come early in Turtletown, TN in 2026?

Spring leaf-out near 37391 came on Feb 21 in 2026, 3 days earlier than the 1991–2020 average (Feb 24), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Turtletown, TN?

Intermediate onions: the longest day near 37391 is 14 h 31 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 37391 change?

Yes. The 2012 USDA map put 37391 in zone 7a; the 2023 map puts it in zone 7b. The newer map uses 1991–2020 data and more weather stations.