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

Planting zone for 72579 — Sulphur Rock, AR

ZIP code 72579 (Sulphur Rock, Independence County) is in USDA zone 7b: the coldest winter night averages 5 to 10 °F. The median last spring frost is March 30 and the first fall frost November 5.

Where ZIP 72579 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 frostMar 30

First frostNov 5

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 Sulphur Rock, 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 Sulphur Rock, AR

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMarch 30median — 50% chance of a later frost

Safe for tender plantsApril 14only 10% chance of frost after

First fall frostNovember 5median — 10% chance by Oct 22

Growing season221 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 16 and returns around November 17.

From the NOAA station Batesville L&D 1, AR — 12 miles away, elevation 289 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 72579

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 16 – Mar 2

SpinachSow outdoors · Feb 16 – Mar 9

Broccoli, cabbageStart indoors · Jan 19 – Feb 2

Broccoli, cabbageTransplant · Mar 9 – Mar 23

Onion setsPlant outdoors · Mar 2 – Mar 16

PotatoesPlant outdoors · Mar 9 – Mar 23

LettuceSow outdoors · Mar 2 – Mar 16

Carrots, beetsSow outdoors · Mar 9 – Mar 23

TomatoesStart indoors · Feb 2 – Feb 16

TomatoesTransplant · Apr 6 – Apr 20

Peppers, eggplantStart indoors · Jan 19 – Feb 2

Peppers, eggplantTransplant · Apr 13 – Apr 27

BeansSow outdoors · Apr 6 – Apr 20

Sweet cornSow outdoors · Apr 6 – Apr 20

Cucumbers, squashSow outdoors · Apr 6 – Apr 20

Fall lettuce, spinachSow outdoors · Sep 10 – Sep 24

GarlicPlant cloves · Oct 22 – Nov 26

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 30) and first fall frost (Nov 5) 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 72579 came on Feb 17 — 8 days earlier than the 1991–2020 average (Feb 25).

average
Feb 252026
Feb 17

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 Sulphur Rock, AR

The soil mapped at the center of ZIP 72579 is Captina — silt loam, moderately well drained.

TextureSilt loama good balance for most vegetables

pH4.7strongly acidic; most vegetables like 6.0–7.0

DrainageModerately well drainednatural drainage class

Organic matter4.5%moderate

Hydrologic groupC/Dslow when drained; wet otherwise

Farmland classFarmland of statewide importanceUSDA classification

Map unit: Captina 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 72579; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Sulphur Rock, AR

Summer high91 °Faverage high, July

Winter low28 °Faverage low, January

Hot days58days a year at 90 °F or more

Freezing nights81nights a year at 32 °F or less

Growing degree days4,774base 50 °F — the season’s usable heat

Longest day14 h 35 mindaylight on June 21

Shortest day9 h 43 mindaylight on December 21

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

Precipitation50.8 inper year, rain and melted snow

Snowfall2 inper year; 2 days with snow on the ground

Average high and low, by month

Precipitation by month inches · ❄ = snowfall

NOAA NCEI U.S. Climate Normals 1991–2020 — temperature: Batesville L&D 1, AR (12 mi away); precipitation: Batesville L&D 1, AR (12 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

Batesville, AR · 9 mi

Strawberry, AR · 12 mi

Arkansas planting zones →

Questions about 72579

What planting zone is ZIP code 72579?

ZIP code 72579 (Sulphur Rock, AR) 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 Sulphur Rock, AR?

The median last spring frost (32 °F) near 72579 is March 30; after April 14 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Batesville L&D 1 station.

When is the first frost in Sulphur Rock, AR?

The median first fall frost near 72579 is November 5, giving a median frost-free growing season of 221 days.

When should I plant tomatoes in 72579?

Start tomato seeds indoors around Feb 2 – Feb 16 and set transplants outside around Apr 6 – Apr 20, one to three weeks after the median last frost.

How much rain and snow does 72579 get?

About 50.8 inches of precipitation a year and 2 inches of snowfall (NOAA 1991–2020 normals, Batesville L&D 1 station).

How hot do summers get in Sulphur Rock, AR?

The average high peaks at 91 °F in July, with about 58 days a year at 90 °F or more.

What kind of soil does 72579 have?

The USDA soil survey maps Captina at the center of ZIP 72579: silt loam, moderately well drained, pH about 4.7 (strongly acidic).

Did spring come early in Sulphur Rock, AR in 2026?

Spring leaf-out near 72579 came on Feb 17 in 2026, 8 days earlier than the 1991–2020 average (Feb 25), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Sulphur Rock, AR?

Intermediate onions: the longest day near 72579 is 14 h 35 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 72579 change?

Yes. The 2012 USDA map put 72579 in zone 7a; the 2023 map puts it in zone 7b. The newer map uses 1991–2020 data and more weather stations.