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

Planting zone for 71929 — Bismarck, AR

ZIP code 71929 (Bismarck, Hot Spring County) is in USDA zone 8a: the coldest winter night averages 10 to 15 °F. The median last spring frost is March 20 and the first fall frost November 10.

Where ZIP 71929 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.

Zone8a10 to 15 °F

Coldest night−12.2 to −9.4 °C

Last frostMar 20

First frostNov 10

2012 zone7b

Was 7b 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 8a means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Bismarck, 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 Bismarck, AR

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMarch 20median — 50% chance of a later frost

Safe for tender plantsApril 7only 10% chance of frost after

First fall frostNovember 10median — 10% chance by Oct 27

Growing season234 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 4 and returns around November 23.

From the NOAA station Degray Lake Sp, AR — 4 miles away, elevation 489 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 71929

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 6 – Feb 20

SpinachSow outdoors · Feb 6 – Feb 27

Broccoli, cabbageStart indoors · Jan 9 – Jan 23

Broccoli, cabbageTransplant · Feb 27 – Mar 13

Onion setsPlant outdoors · Feb 20 – Mar 6

PotatoesPlant outdoors · Feb 27 – Mar 13

LettuceSow outdoors · Feb 20 – Mar 6

Carrots, beetsSow outdoors · Feb 27 – Mar 13

TomatoesStart indoors · Jan 23 – Feb 6

TomatoesTransplant · Mar 27 – Apr 10

Peppers, eggplantStart indoors · Jan 9 – Jan 23

Peppers, eggplantTransplant · Apr 3 – Apr 17

BeansSow outdoors · Mar 27 – Apr 10

Sweet cornSow outdoors · Mar 27 – Apr 10

Cucumbers, squashSow outdoors · Mar 27 – Apr 10

Fall lettuce, spinachSow outdoors · Sep 15 – Sep 29

GarlicPlant cloves · Oct 27 – Dec 1

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 20) and first fall frost (Nov 10) 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 71929 came on Feb 13 — 3 days earlier than the 1991–2020 average (Feb 16).

average
Feb 162026
Feb 13

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 8a in Arkansas

516 plants native to the lower 48 states, recorded in Arkansas, and rated by the USDA to survive 10 °F or colder — the bottom of zone 8a. 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 Bismarck, AR.

Soil in Bismarck, AR

The soil mapped at the center of ZIP 71929 is Bonnerdale — fine sandy loam, somewhat poorly drained.

TextureFine sandy loamdrains and warms fast; dries out and needs more feeding

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

DrainageSomewhat poorly drainedconsider raised beds

Organic matter1.75%low — add compost

Hydrologic groupB/Dmoderate when drained; wet otherwise

Farmland classprime farmlandUSDA classification

Map unit: Bonnerdale fine sandy loam, 0 to 5 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 71929; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Bismarck, AR

Summer high91 °Faverage high, July

Winter low30 °Faverage low, January

Hot days56days a year at 90 °F or more

Freezing nights58nights a year at 32 °F or less

Growing degree days5,023base 50 °F — the season’s usable heat

Longest day14 h 27 mindaylight on June 21

Shortest day9 h 52 mindaylight on December 21

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

Precipitation58.1 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: Degray Lake Sp, AR (4 mi away); precipitation: Degray Lake Sp, AR (4 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 8a.

719648a

Pearcy, AR · 10 mi

719138a

Hot Springs National Park, AR · 10 mi

719428a

Friendship, AR · 11 mi

719418a

Donaldson, AR · 12 mi

719338a

Bonnerdale, AR · 14 mi

719208a

Alpine, AR · 14 mi

719988a

Arkadelphia, AR · 14 mi

719218a

Amity, AR · 14 mi

Arkansas planting zones →

Questions about 71929

What planting zone is ZIP code 71929?

ZIP code 71929 (Bismarck, AR) is in USDA hardiness zone 8a on the 2023 map: the coldest night of an average winter reaches 10 to 15 °F (−12.2 to −9.4 °C).

When is the last frost in Bismarck, AR?

The median last spring frost (32 °F) near 71929 is March 20; after April 7 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Degray Lake Sp station.

When is the first frost in Bismarck, AR?

The median first fall frost near 71929 is November 10, giving a median frost-free growing season of 234 days.

When should I plant tomatoes in 71929?

Start tomato seeds indoors around Jan 23 – Feb 6 and set transplants outside around Mar 27 – Apr 10, one to three weeks after the median last frost.

How much rain and snow does 71929 get?

About 58.1 inches of precipitation a year (NOAA 1991–2020 normals, Degray Lake Sp station).

How hot do summers get in Bismarck, AR?

The average high peaks at 91 °F in July, with about 56 days a year at 90 °F or more.

What kind of soil does 71929 have?

The USDA soil survey maps Bonnerdale at the center of ZIP 71929: fine sandy loam, somewhat poorly drained, pH about 5.3 (strongly acidic).

Did spring come early in Bismarck, AR in 2026?

Spring leaf-out near 71929 came on Feb 13 in 2026, 3 days earlier than the 1991–2020 average (Feb 16), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Bismarck, AR?

Intermediate onions: the longest day near 71929 is 14 h 27 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 71929 change?

Yes. The 2012 USDA map put 71929 in zone 7b; the 2023 map puts it in zone 8a. The newer map uses 1991–2020 data and more weather stations.