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

Planting zone for 37121 — Mount Juliet, TN

ZIP code 37121 (Mount Juliet, Wilson County) is in USDA zone 7b: the coldest winter night averages 5 to 10 °F. The median last spring frost is April 1 and the first fall frost November 4.

Where ZIP 37121 is

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 1

First frostNov 4

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 Mount Juliet, 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 Mount Juliet, TN

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 1median — 50% chance of a later frost

Safe for tender plantsApril 17only 10% chance of frost after

First fall frostNovember 4median — 10% chance by Oct 23

Growing season216 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 20 and returns around November 15.

From the NOAA station Old Hickory WFO, TN — 4 miles away, elevation 591 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 37121

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 18 – Mar 4

SpinachSow outdoors · Feb 18 – Mar 11

Broccoli, cabbageStart indoors · Jan 21 – Feb 4

Broccoli, cabbageTransplant · Mar 11 – Mar 25

Onion setsPlant outdoors · Mar 4 – Mar 18

PotatoesPlant outdoors · Mar 11 – Mar 25

LettuceSow outdoors · Mar 4 – Mar 18

Carrots, beetsSow outdoors · Mar 11 – Mar 25

TomatoesStart indoors · Feb 4 – Feb 18

TomatoesTransplant · Apr 8 – Apr 22

Peppers, eggplantStart indoors · Jan 21 – Feb 4

Peppers, eggplantTransplant · Apr 15 – Apr 29

BeansSow outdoors · Apr 8 – Apr 22

Sweet cornSow outdoors · Apr 8 – Apr 22

Cucumbers, squashSow outdoors · Apr 8 – Apr 22

Fall lettuce, spinachSow outdoors · Sep 9 – Sep 23

GarlicPlant cloves · Oct 21 – Nov 25

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Apr 1) and first fall frost (Nov 4) 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 37121 came on Feb 25 — about the same time as the 1991–2020 average (Feb 25).

average
Feb 252026
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 Mount Juliet, TN.

Soil in Mount Juliet, TN

The soil mapped at the center of ZIP 37121 is Talbott — silt loam, well drained.

TextureSilt loama good balance for most vegetables

pH5.6moderately acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter1.25%low — add compost

Hydrologic groupCwater soaks in slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Talbott silt loam, 5 to 20 percent slopes, eroded, rocky.

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 37121; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Mount Juliet, TN

Summer high89 °Faverage high, July

Winter low28 °Faverage low, January

Hot days42days a year at 90 °F or more

Freezing nights69nights a year at 32 °F or less

Growing degree days4,558base 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

Precipitation53.9 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: Old Hickory WFO, TN (4 mi away); precipitation: Mount Juliet 2.9 Wsw, TN (3 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 7b.

371227b

Mount Juliet, TN · 2 mi

370767b

Hermitage, TN · 5 mi

371387b

Old Hickory, TN · 6 mi

372147b

Nashville, TN · 8 mi

370777b

Hendersonville, TN · 9 mi

372177b

Nashville, TN · 10 mi

371157b

Madison, TN · 11 mi

370757b

Hendersonville, TN · 11 mi

All 2 ZIP codes in Mount Juliet → · Tennessee planting zones →

Questions about 37121

What planting zone is ZIP code 37121?

ZIP code 37121 (Mount Juliet, 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 Mount Juliet, TN?

The median last spring frost (32 °F) near 37121 is April 1; after April 17 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Old Hickory WFO station.

When is the first frost in Mount Juliet, TN?

The median first fall frost near 37121 is November 4, giving a median frost-free growing season of 216 days.

When should I plant tomatoes in 37121?

Start tomato seeds indoors around Feb 4 – Feb 18 and set transplants outside around Apr 8 – Apr 22, one to three weeks after the median last frost.

How much rain and snow does 37121 get?

About 53.9 inches of precipitation a year (NOAA 1991–2020 normals, Mount Juliet 2.9 Wsw station).

How hot do summers get in Mount Juliet, TN?

The average high peaks at 89 °F in July, with about 42 days a year at 90 °F or more.

What kind of soil does 37121 have?

The USDA soil survey maps Talbott at the center of ZIP 37121: silt loam, well drained, pH about 5.6 (moderately acidic).

Did spring come early in Mount Juliet, TN in 2026?

Spring leaf-out near 37121 came on Feb 25 in 2026, about the same as the 1991–2020 average (Feb 25), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Mount Juliet, TN?

Intermediate onions: the longest day near 37121 is 14 h 38 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 37121 change?

Yes. The 2012 USDA map put 37121 in zone 7a; the 2023 map puts it in zone 7b. The newer map uses 1991–2020 data and more weather stations.