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

Planting zone for 37779 — Luttrell, TN

ZIP code 37779 (Luttrell, Union County) is in USDA zone 7b: the coldest winter night averages 5 to 10 °F. The median last spring frost is April 22 and the first fall frost October 25.

Where ZIP 37779 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 22

First frostOct 25

2012 zone6b

Was 6b on the 2012 map — a full 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 Luttrell, 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 Luttrell, TN

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 22median — 50% chance of a later frost

Safe for tender plantsMay 9only 10% chance of frost after

First fall frostOctober 25median — 10% chance by Oct 11

Growing season184 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 7 and returns around November 3.

From the NOAA station Norris, TN — 17 miles away, elevation 1,109 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 37779

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 11 – Mar 25

SpinachSow outdoors · Mar 11 – Apr 1

Broccoli, cabbageStart indoors · Feb 11 – Feb 25

Broccoli, cabbageTransplant · Apr 1 – Apr 15

Onion setsPlant outdoors · Mar 25 – Apr 8

PotatoesPlant outdoors · Apr 1 – Apr 15

LettuceSow outdoors · Mar 25 – Apr 8

Carrots, beetsSow outdoors · Apr 1 – Apr 15

TomatoesStart indoors · Feb 25 – Mar 11

TomatoesTransplant · Apr 29 – May 13

Peppers, eggplantStart indoors · Feb 11 – Feb 25

Peppers, eggplantTransplant · May 6 – May 20

BeansSow outdoors · Apr 29 – May 13

Sweet cornSow outdoors · Apr 29 – May 13

Cucumbers, squashSow outdoors · Apr 29 – May 13

Fall lettuce, spinachSow outdoors · Aug 30 – Sep 13

GarlicPlant cloves · Oct 11 – Nov 15

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 22) and first fall frost (Oct 25) 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 37779 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 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 Luttrell, TN.

Soil in Luttrell, TN

The soil mapped at the center of ZIP 37779 is Claiborne — silt loam, well drained.

TextureSilt loama good balance for most vegetables

pH5.3strongly acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter2%moderate

Hydrologic groupBwater soaks in moderately

Farmland classNot prime farmlandUSDA classification

Map unit: Claiborne silt loam, hilly phase.

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 37779; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Luttrell, TN

Summer high85 °Faverage high, July

Winter low25 °Faverage low, January

Hot days17days a year at 90 °F or more

Freezing nights101nights a year at 32 °F or less

Growing degree days3,691base 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

Precipitation53.4 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: Norris, TN (17 mi away); precipitation: Maynardville 0.6 E, TN (3 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 7b.

378487b

Powder Springs, TN · 5 mi

378077b

Maynardville, TN · 5 mi

Sharps Chapel, TN · 11 mi

379387b

Knoxville, TN · 12 mi

378717b

Strawberry Plains, TN · 12 mi

Tennessee planting zones →

Questions about 37779

What planting zone is ZIP code 37779?

ZIP code 37779 (Luttrell, 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 Luttrell, TN?

The median last spring frost (32 °F) near 37779 is April 22; after May 9 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Norris station.

When is the first frost in Luttrell, TN?

The median first fall frost near 37779 is October 25, giving a median frost-free growing season of 184 days.

When should I plant tomatoes in 37779?

Start tomato seeds indoors around Feb 25 – Mar 11 and set transplants outside around Apr 29 – May 13, one to three weeks after the median last frost.

How much rain and snow does 37779 get?

About 53.4 inches of precipitation a year (NOAA 1991–2020 normals, Maynardville 0.6 E station).

How hot do summers get in Luttrell, TN?

The average high peaks at 85 °F in July, with about 17 days a year at 90 °F or more.

What kind of soil does 37779 have?

The USDA soil survey maps Claiborne at the center of ZIP 37779: silt loam, well drained, pH about 5.3 (strongly acidic).

Did spring come early in Luttrell, TN in 2026?

Spring leaf-out near 37779 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 Luttrell, TN?

Intermediate onions: the longest day near 37779 is 14 h 38 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 37779 change?

Yes. The 2012 USDA map put 37779 in zone 6b; the 2023 map puts it in zone 7b. The newer map uses 1991–2020 data and more weather stations.