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

Planting zone for 37891 — Whitesburg, TN

ZIP code 37891 (Whitesburg, Hamblen County) is in USDA zone 7b: the coldest winter night averages 5 to 10 °F. The median last spring frost is April 14 and the first fall frost October 24.

Where ZIP 37891 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 14

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 Whitesburg, 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 Whitesburg, TN

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 14median — 50% chance of a later frost

Safe for tender plantsMay 3only 10% chance of frost after

First fall frostOctober 24median — 10% chance by Oct 11

Growing season192 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 2 and returns around November 1.

From the NOAA station Rogersville 1 Ne, TN — 12 miles away, elevation 1,355 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 37891

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 3 – Mar 17

SpinachSow outdoors · Mar 3 – Mar 24

Broccoli, cabbageStart indoors · Feb 3 – Feb 17

Broccoli, cabbageTransplant · Mar 24 – Apr 7

Onion setsPlant outdoors · Mar 17 – Mar 31

PotatoesPlant outdoors · Mar 24 – Apr 7

LettuceSow outdoors · Mar 17 – Mar 31

Carrots, beetsSow outdoors · Mar 24 – Apr 7

TomatoesStart indoors · Feb 17 – Mar 3

TomatoesTransplant · Apr 21 – May 5

Peppers, eggplantStart indoors · Feb 3 – Feb 17

Peppers, eggplantTransplant · Apr 28 – May 12

BeansSow outdoors · Apr 21 – May 5

Sweet cornSow outdoors · Apr 21 – May 5

Cucumbers, squashSow outdoors · Apr 21 – May 5

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 14) 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 37891 came on Mar 1 — about the same time as the 1991–2020 average (Mar 1).

average
Mar 12026
Mar 1

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 Whitesburg, TN.

Soil in Whitesburg, TN

The soil mapped at the center of ZIP 37891 is Dandridge — channery silty clay loam, excessively drained.

TextureChannery silty clay loamholds water and nutrients; slow to drain and warm up

pH7.0neutral; most vegetables like 6.0–7.0

DrainageExcessively drainednatural drainage class

Organic matter1.25%low — add compost

Hydrologic groupDwater soaks in very slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Dandridge shaly silty clay loam, hilly, 12 to 25 percent slope.

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 37891; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Whitesburg, TN

Summer high86 °Faverage high, July

Winter low26 °Faverage low, January

Hot days18days a year at 90 °F or more

Freezing nights87nights a year at 32 °F or less

Growing degree days3,883base 50 °F — the season’s usable heat

Longest day14 h 38 mindaylight on June 21

Shortest day9 h 41 mindaylight on December 21

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

Precipitation46.8 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: Rogersville 1 Ne, TN (12 mi away); precipitation: Bulls Gap 3.6 W, TN (2 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 7b.

378607b

Russellville, TN · 4 mi

377117b

Bulls Gap, TN · 5 mi

378117b

Mooresburg, TN · 6 mi

378107b

Mohawk, TN · 8 mi

378157b

Morristown, TN · 9 mi

378167b

Morristown, TN · 9 mi

377087b

Bean Station, TN · 10 mi

378137b

Morristown, TN · 10 mi

Tennessee planting zones →

Questions about 37891

What planting zone is ZIP code 37891?

ZIP code 37891 (Whitesburg, 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 Whitesburg, TN?

The median last spring frost (32 °F) near 37891 is April 14; after May 3 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Rogersville 1 Ne station.

When is the first frost in Whitesburg, TN?

The median first fall frost near 37891 is October 24, giving a median frost-free growing season of 192 days.

When should I plant tomatoes in 37891?

Start tomato seeds indoors around Feb 17 – Mar 3 and set transplants outside around Apr 21 – May 5, one to three weeks after the median last frost.

How much rain and snow does 37891 get?

About 46.8 inches of precipitation a year (NOAA 1991–2020 normals, Bulls Gap 3.6 W station).

How hot do summers get in Whitesburg, TN?

The average high peaks at 86 °F in July, with about 18 days a year at 90 °F or more.

What kind of soil does 37891 have?

The USDA soil survey maps Dandridge at the center of ZIP 37891: channery silty clay loam, excessively drained, pH about 7.0 (neutral).

Did spring come early in Whitesburg, TN in 2026?

Spring leaf-out near 37891 came on Mar 1 in 2026, about the same as the 1991–2020 average (Mar 1), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Whitesburg, TN?

Intermediate onions: the longest day near 37891 is 14 h 38 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 37891 change?

Yes. The 2012 USDA map put 37891 in zone 7a; the 2023 map puts it in zone 7b. The newer map uses 1991–2020 data and more weather stations.