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

Planting zone for 72554 — Mammoth Spring, AR

ZIP code 72554 (Mammoth Spring, Fulton County) is in USDA zone 7a: the coldest winter night averages 0 to 5 °F. The median last spring frost is April 12 and the first fall frost October 24.

Where ZIP 72554 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 12

First frostOct 24

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 Mammoth Spring, AR…

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 Mammoth Spring, AR

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostApril 12median — 50% chance of a later frost

Safe for tender plantsApril 27only 10% chance of frost after

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

Growing season194 daysfrost-free, median

A hard freeze (28 °F) usually ends around April 1 and returns around November 3.

From the NOAA station Mammoth Spring, AR — 4 miles away, elevation 502 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 72554

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Mar 1 – Mar 15

SpinachSow outdoors · Mar 1 – Mar 22

Broccoli, cabbageStart indoors · Feb 1 – Feb 15

Broccoli, cabbageTransplant · Mar 22 – Apr 5

Onion setsPlant outdoors · Mar 15 – Mar 29

PotatoesPlant outdoors · Mar 22 – Apr 5

LettuceSow outdoors · Mar 15 – Mar 29

Carrots, beetsSow outdoors · Mar 22 – Apr 5

TomatoesStart indoors · Feb 15 – Mar 1

TomatoesTransplant · Apr 19 – May 3

Peppers, eggplantStart indoors · Feb 1 – Feb 15

Peppers, eggplantTransplant · Apr 26 – May 10

BeansSow outdoors · Apr 19 – May 3

Sweet cornSow outdoors · Apr 19 – May 3

Cucumbers, squashSow outdoors · Apr 19 – May 3

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 12) 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 72554 came on Feb 24 — 7 days earlier than the 1991–2020 average (Mar 3).

average
Mar 32026
Feb 24

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 7a in Arkansas

501 plants native to the lower 48 states, recorded in Arkansas, and rated by the USDA to survive 0 °F or colder — the bottom of zone 7a. 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 Mammoth Spring, AR.

Soil in Mammoth Spring, AR

The soil mapped at the center of ZIP 72554 is Gepp — very gravelly silt loam, well drained.

TextureVery gravelly silt loama good balance for most vegetables

pH5.8moderately acidic; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter2.5%moderate

Hydrologic groupDwater soaks in very slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Gepp very gravelly silt loam, 3 to 8 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 72554; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Mammoth Spring, AR

Summer high90 °Faverage high, July

Winter low23 °Faverage low, January

Hot days49days a year at 90 °F or more

Freezing nights103nights a year at 32 °F or less

Growing degree days4,294base 50 °F — the season’s usable heat

Longest day14 h 39 mindaylight on June 21

Shortest day9 h 40 mindaylight on December 21

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

Precipitation48.8 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: Mammoth Spring, AR (4 mi away); precipitation: Mammoth Spring, AR (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

3 of the 8 nearest ZIP codes are in a different zone — elevation and distance from water change winter lows quickly.

725257b

Cherokee Village, AR · 9 mi

Cherokee Village, AR · 11 mi

Koshkonong, MO · 13 mi

725137a

Ash Flat, AR · 16 mi

Arkansas planting zones →

Questions about 72554

What planting zone is ZIP code 72554?

ZIP code 72554 (Mammoth Spring, AR) 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 Mammoth Spring, AR?

The median last spring frost (32 °F) near 72554 is April 12; after April 27 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Mammoth Spring station.

When is the first frost in Mammoth Spring, AR?

The median first fall frost near 72554 is October 24, giving a median frost-free growing season of 194 days.

When should I plant tomatoes in 72554?

Start tomato seeds indoors around Feb 15 – Mar 1 and set transplants outside around Apr 19 – May 3, one to three weeks after the median last frost.

How much rain and snow does 72554 get?

About 48.8 inches of precipitation a year (NOAA 1991–2020 normals, Mammoth Spring station).

How hot do summers get in Mammoth Spring, AR?

The average high peaks at 90 °F in July, with about 49 days a year at 90 °F or more.

What kind of soil does 72554 have?

The USDA soil survey maps Gepp at the center of ZIP 72554: very gravelly silt loam, well drained, pH about 5.8 (moderately acidic).

Did spring come early in Mammoth Spring, AR in 2026?

Spring leaf-out near 72554 came on Feb 24 in 2026, 7 days earlier than the 1991–2020 average (Mar 3), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Mammoth Spring, AR?

Intermediate onions: the longest day near 72554 is 14 h 39 min, so day-neutral types bulb best; long-day varieties may not bulb fully.