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

Planting zone for 73434 — Foster, OK

ZIP code 73434 (Foster, Stephens County) is in USDA zone 7b: the coldest winter night averages 5 to 10 °F. The median last spring frost is March 28 and the first fall frost November 7.

Where ZIP 73434 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 28

First frostNov 7

2012 zone7b

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 7b means →

Frost forecast — next 7 nights

live from the National Weather Service

Loading the forecast for Foster, OK…

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 Foster, OK

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMarch 28median — 50% chance of a later frost

Safe for tender plantsApril 18only 10% chance of frost after

First fall frostNovember 7median — 10% chance by Oct 23

Growing season227 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 12 and returns around November 16.

From the NOAA station Velma 7nw Mesonet, OK — 12 miles away, elevation 1,119 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 73434

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 14 – Feb 28

SpinachSow outdoors · Feb 14 – Mar 7

Broccoli, cabbageStart indoors · Jan 17 – Jan 31

Broccoli, cabbageTransplant · Mar 7 – Mar 21

Onion setsPlant outdoors · Feb 28 – Mar 14

PotatoesPlant outdoors · Mar 7 – Mar 21

LettuceSow outdoors · Feb 28 – Mar 14

Carrots, beetsSow outdoors · Mar 7 – Mar 21

TomatoesStart indoors · Jan 31 – Feb 14

TomatoesTransplant · Apr 4 – Apr 18

Peppers, eggplantStart indoors · Jan 17 – Jan 31

Peppers, eggplantTransplant · Apr 11 – Apr 25

BeansSow outdoors · Apr 4 – Apr 18

Sweet cornSow outdoors · Apr 4 – Apr 18

Cucumbers, squashSow outdoors · Apr 4 – Apr 18

Fall lettuce, spinachSow outdoors · Sep 12 – Sep 26

GarlicPlant cloves · Oct 24 – Nov 28

Start seeds indoorsSow or plant outdoorsFall plantingMedian last & first frost

Counted from the median last spring frost (Mar 28) and first fall frost (Nov 7) 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 73434 came on Feb 11 — 8 days earlier than the 1991–2020 average (Feb 19).

average
Feb 192026
Feb 11

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 Oklahoma

518 plants native to the lower 48 states, recorded in Oklahoma, 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 Foster, OK.

Soil in Foster, OK

The soil mapped at the center of ZIP 73434 is Zaneis — loam, well drained.

TextureLoama good balance for most vegetables

pH6.5neutral; most vegetables like 6.0–7.0

DrainageWell drainednatural drainage class

Organic matter2%moderate

Hydrologic groupCwater soaks in slowly

Farmland classNot prime farmlandUSDA classification

Map unit: Zaneis-Grainola-Lucien complex, 5 to 12 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 73434; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Foster, OK

Summer high95 °Faverage high, August

Winter low30 °Faverage low, January

Hot days86days a year at 90 °F or more

Freezing nights65nights a year at 32 °F or less

Growing degree days5,485base 50 °F — the season’s usable heat

Longest day14 h 29 mindaylight on June 21

Shortest day9 h 50 mindaylight on December 21

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

Precipitation35.1 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: Velma 7nw Mesonet, OK (12 mi away); precipitation: Tussy, OK (8 mi away). Daylight is calculated from latitude.

Nearby ZIP codes

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

734888a

Tussy, OK · 9 mi

734337b

Elmore City, OK · 9 mi

734258a

Countyline, OK · 11 mi

Ratliff City, OK · 14 mi

Oklahoma planting zones →

Questions about 73434

What planting zone is ZIP code 73434?

ZIP code 73434 (Foster, OK) 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 Foster, OK?

The median last spring frost (32 °F) near 73434 is March 28; after April 18 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Velma 7nw Mesonet station.

When is the first frost in Foster, OK?

The median first fall frost near 73434 is November 7, giving a median frost-free growing season of 227 days.

When should I plant tomatoes in 73434?

Start tomato seeds indoors around Jan 31 – Feb 14 and set transplants outside around Apr 4 – Apr 18, one to three weeks after the median last frost.

How much rain and snow does 73434 get?

About 35.1 inches of precipitation a year (NOAA 1991–2020 normals, Tussy station).

How hot do summers get in Foster, OK?

The average high peaks at 95 °F in August, with about 86 days a year at 90 °F or more.

What kind of soil does 73434 have?

The USDA soil survey maps Zaneis at the center of ZIP 73434: loam, well drained, pH about 6.5 (neutral).

Did spring come early in Foster, OK in 2026?

Spring leaf-out near 73434 came on Feb 11 in 2026, 8 days earlier than the 1991–2020 average (Feb 19), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Foster, OK?

Intermediate onions: the longest day near 73434 is 14 h 29 min, so day-neutral types bulb best; long-day varieties may not bulb fully.