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

Planting zone for 72435 — Knobel, AR

ZIP code 72435 (Knobel, Clay County) is in USDA zone 7b: the coldest winter night averages 5 to 10 °F. The median last spring frost is March 27 and the first fall frost November 4.

Where ZIP 72435 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 27

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 Knobel, 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 Knobel, AR

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMarch 27median — 50% chance of a later frost

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

First fall frostNovember 4median — 10% chance by Oct 22

Growing season224 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 15 and returns around November 16.

From the NOAA station Corning, AR — 7 miles away, elevation 299 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 72435

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 13 – Feb 27

SpinachSow outdoors · Feb 13 – Mar 6

Broccoli, cabbageStart indoors · Jan 16 – Jan 30

Broccoli, cabbageTransplant · Mar 6 – Mar 20

Onion setsPlant outdoors · Feb 27 – Mar 13

PotatoesPlant outdoors · Mar 6 – Mar 20

LettuceSow outdoors · Feb 27 – Mar 13

Carrots, beetsSow outdoors · Mar 6 – Mar 20

TomatoesStart indoors · Jan 30 – Feb 13

TomatoesTransplant · Apr 3 – Apr 17

Peppers, eggplantStart indoors · Jan 16 – Jan 30

Peppers, eggplantTransplant · Apr 10 – Apr 24

BeansSow outdoors · Apr 3 – Apr 17

Sweet cornSow outdoors · Apr 3 – Apr 17

Cucumbers, squashSow outdoors · Apr 3 – Apr 17

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 (Mar 27) 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 72435 came on Feb 24 — 4 days earlier than the 1991–2020 average (Feb 28).

average
Feb 282026
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 7b in Arkansas

505 plants native to the lower 48 states, recorded in Arkansas, 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 Knobel, AR.

Soil in Knobel, AR

The soil mapped at the center of ZIP 72435 is Foley — silt loam, poorly drained.

TextureSilt loama good balance for most vegetables

pH5.9moderately acidic; most vegetables like 6.0–7.0

DrainagePoorly drainedconsider raised beds

Organic matter1.25%low — add compost

Hydrologic groupDwater soaks in very slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Foley silt loam, 0 to 1 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 72435; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Knobel, AR

Summer high90 °Faverage high, July

Winter low28 °Faverage low, January

Hot days54days a year at 90 °F or more

Freezing nights70nights a year at 32 °F or less

Growing degree days4,852base 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

Precipitation48.9 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: Corning, AR (7 mi away); precipitation: Lafe 1.8 W, AR (7 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

All 8 nearest ZIP codes share zone 7b.

724537b

Peach Orchard, AR · 6 mi

Delaplaine, AR · 12 mi

724437b

Marmaduke, AR · 12 mi

724417b

Mc Dougal, AR · 12 mi

724627b

Reyno, AR · 13 mi

Arkansas planting zones →

Questions about 72435

What planting zone is ZIP code 72435?

ZIP code 72435 (Knobel, 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 Knobel, AR?

The median last spring frost (32 °F) near 72435 is March 27; after April 10 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Corning station.

When is the first frost in Knobel, AR?

The median first fall frost near 72435 is November 4, giving a median frost-free growing season of 224 days.

When should I plant tomatoes in 72435?

Start tomato seeds indoors around Jan 30 – Feb 13 and set transplants outside around Apr 3 – Apr 17, one to three weeks after the median last frost.

How much rain and snow does 72435 get?

About 48.9 inches of precipitation a year (NOAA 1991–2020 normals, Lafe 1.8 W station).

How hot do summers get in Knobel, AR?

The average high peaks at 90 °F in July, with about 54 days a year at 90 °F or more.

What kind of soil does 72435 have?

The USDA soil survey maps Foley at the center of ZIP 72435: silt loam, poorly drained, pH about 5.9 (moderately acidic).

Did spring come early in Knobel, AR in 2026?

Spring leaf-out near 72435 came on Feb 24 in 2026, 4 days earlier than the 1991–2020 average (Feb 28), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Knobel, AR?

Intermediate onions: the longest day near 72435 is 14 h 38 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 72435 change?

Yes. The 2012 USDA map put 72435 in zone 7a; the 2023 map puts it in zone 7b. The newer map uses 1991–2020 data and more weather stations.