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

Planting zone for 37339 — Gruetli Laager, TN

ZIP code 37339 (Gruetli Laager, Grundy County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is April 21 and the first fall frost October 20.

Where ZIP 37339 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 21
First frostOct 20
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 Gruetli Laager, 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 Gruetli Laager, TN

JanFebMarAprMayJunJulAugSepOctNovDec
Blue: frost possible · fading green: frost risk falling or rising (90% → 10%) · green: frost-free
Last spring frostApril 21median — 50% chance of a later frost
Safe for tender plantsMay 10only 10% chance of frost after
First fall frostOctober 20median — 10% chance by Oct 7
Growing season182 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 7 and returns around October 30.

From the NOAA station Coalmont, TN — 4 miles away, elevation 1,857 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 37339

JanFebMarAprMayJunJulAugSepOctNovDec
PeasSow outdoors · Mar 10 – Mar 24
SpinachSow outdoors · Mar 10 – Mar 31
Broccoli, cabbageStart indoors · Feb 10 – Feb 24
Broccoli, cabbageTransplant · Mar 31 – Apr 14
Onion setsPlant outdoors · Mar 24 – Apr 7
PotatoesPlant outdoors · Mar 31 – Apr 14
LettuceSow outdoors · Mar 24 – Apr 7
Carrots, beetsSow outdoors · Mar 31 – Apr 14
TomatoesStart indoors · Feb 24 – Mar 10
TomatoesTransplant · Apr 28 – May 12
Peppers, eggplantStart indoors · Feb 10 – Feb 24
Peppers, eggplantTransplant · May 5 – May 19
BeansSow outdoors · Apr 28 – May 12
Sweet cornSow outdoors · Apr 28 – May 12
Cucumbers, squashSow outdoors · Apr 28 – May 12
Fall lettuce, spinachSow outdoors · Aug 25 – Sep 8
GarlicPlant cloves · Oct 6 – Nov 10
Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 21) and first fall frost (Oct 20) 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 37339 came on Feb 25 — 6 days earlier than the 1991–2020 average (Mar 3).

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).

Soil in Gruetli Laager, TN

The soil mapped at the center of ZIP 37339 is Beersheba — loam, well drained.

TextureLoama good balance for most vegetables
pH4.6strongly acidic; most vegetables like 6.0–7.0
DrainageWell drainednatural drainage class
Organic matter2.3%moderate
Hydrologic groupBwater soaks in moderately
Farmland classprime farmlandUSDA classification

Map unit: Beersheba loam, 2 to 6 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 37339; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Gruetli Laager, TN

Summer high83 °Faverage high, July
Winter low26 °Faverage low, January
Hot days8days a year at 90 °F or more
Freezing nights103nights a year at 32 °F or less
Growing degree days3,486base 50 °F — the season’s usable heat
Longest day14 h 33 mindaylight on June 21
Shortest day9 h 46 mindaylight on December 21
Onions to growIntermediateday-neutral types bulb best; long-day varieties may not bulb fully
Precipitation60.5 inper year, rain and melted snow

Average high and low, by month

20°30°40°50°60°70°80°90°32 °FJanuary: average high 45 °F, low 26 °F 45°26° JanFebruary: average high 49 °F, low 28 °F 49°28° FebMarch: average high 57 °F, low 35 °F 57°35° MarApril: average high 66 °F, low 42 °F 66°42° AprMay: average high 74 °F, low 52 °F 74°52° MayJune: average high 80 °F, low 60 °F 80°60° JunJuly: average high 83 °F, low 63 °F 83°63° JulAugust: average high 83 °F, low 62 °F 83°62° AugSeptember: average high 78 °F, low 55 °F 78°55° SepOctober: average high 68 °F, low 43 °F 68°43° OctNovember: average high 57 °F, low 34 °F 57°34° NovDecember: average high 48 °F, low 29 °F 48°29° Dec

Precipitation by month inches

0″2″4″6″January: 5.66 in precipitation 5.7 JanFebruary: 5.43 in precipitation 5.4 FebMarch: 5.74 in precipitation 5.7 MarApril: 5.73 in precipitation 5.7 AprMay: 4.72 in precipitation 4.7 MayJune: 4.99 in precipitation 5.0 JunJuly: 5.02 in precipitation 5.0 JulAugust: 4.41 in precipitation 4.4 AugSeptember: 4.26 in precipitation 4.3 SepOctober: 3.57 in precipitation 3.6 OctNovember: 4.57 in precipitation 4.6 NovDecember: 6.39 in precipitation 6.4 Dec

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Coalmont, TN (4 mi away); precipitation: Gruetli-Laager 1.3 E, 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.

373137a
Coalmont, TN · 4 mi
373657b
Palmer, TN · 7 mi
373057a
Beersheba Springs, TN · 7 mi
373877a
Tracy City, TN · 8 mi
373017b
Altamont, TN · 10 mi
373667b
Pelham, TN · 11 mi
373977b
Whitwell, TN · 13 mi
373277b
Dunlap, TN · 14 mi

Tennessee planting zones →

Questions about 37339

What planting zone is ZIP code 37339?

ZIP code 37339 (Gruetli Laager, 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 Gruetli Laager, TN?

The median last spring frost (32 °F) near 37339 is April 21; after May 10 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Coalmont station.

When is the first frost in Gruetli Laager, TN?

The median first fall frost near 37339 is October 20, giving a median frost-free growing season of 182 days.

When should I plant tomatoes in 37339?

Start tomato seeds indoors around Feb 24 – Mar 10 and set transplants outside around Apr 28 – May 12, one to three weeks after the median last frost.

How much rain and snow does 37339 get?

About 60.5 inches of precipitation a year (NOAA 1991–2020 normals, Gruetli-Laager 1.3 E station).

How hot do summers get in Gruetli Laager, TN?

The average high peaks at 83 °F in July, with about 8 days a year at 90 °F or more.

What kind of soil does 37339 have?

The USDA soil survey maps Beersheba at the center of ZIP 37339: loam, well drained, pH about 4.6 (strongly acidic).

Did spring come early in Gruetli Laager, TN in 2026?

Spring leaf-out near 37339 came on Feb 25 in 2026, 6 days earlier than the 1991–2020 average (Mar 3), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Gruetli Laager, TN?

Intermediate onions: the longest day near 37339 is 14 h 33 min, so day-neutral types bulb best; long-day varieties may not bulb fully.