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

Planting zone for 74055 — Owasso, OK

ZIP code 74055 (Owasso, Tulsa County) is in USDA zone 7b: the coldest winter night averages 5 to 10 °F. The median last spring frost is March 31 and the first fall frost November 4.

Where ZIP 74055 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 31

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 Owasso, 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 Owasso, OK

JanFebMarAprMayJunJulAugSepOctNovDec

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

Last spring frostMarch 31median — 50% chance of a later frost

Safe for tender plantsApril 15only 10% chance of frost after

First fall frostNovember 4median — 10% chance by Oct 20

Growing season220 daysfrost-free, median

A hard freeze (28 °F) usually ends around March 17 and returns around November 13.

From the NOAA station Tulsa Intl Airport, OK — 7 miles away, elevation 650 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 74055

JanFebMarAprMayJunJulAugSepOctNovDec

PeasSow outdoors · Feb 17 – Mar 3

SpinachSow outdoors · Feb 17 – Mar 10

Broccoli, cabbageStart indoors · Jan 20 – Feb 3

Broccoli, cabbageTransplant · Mar 10 – Mar 24

Onion setsPlant outdoors · Mar 3 – Mar 17

PotatoesPlant outdoors · Mar 10 – Mar 24

LettuceSow outdoors · Mar 3 – Mar 17

Carrots, beetsSow outdoors · Mar 10 – Mar 24

TomatoesStart indoors · Feb 3 – Feb 17

TomatoesTransplant · Apr 7 – Apr 21

Peppers, eggplantStart indoors · Jan 20 – Feb 3

Peppers, eggplantTransplant · Apr 14 – Apr 28

BeansSow outdoors · Apr 7 – Apr 21

Sweet cornSow outdoors · Apr 7 – Apr 21

Cucumbers, squashSow outdoors · Apr 7 – Apr 21

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 31) 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 74055 came on Feb 12 — 15 days earlier than the 1991–2020 average (Feb 27).

average
Feb 272026
Feb 12

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 Owasso, OK.

Soil in Owasso, OK

The soil mapped at the center of ZIP 74055 is Dennis — silt loam, somewhat poorly drained.

TextureSilt loama good balance for most vegetables

pH5.6moderately acidic; most vegetables like 6.0–7.0

DrainageSomewhat poorly drainedconsider raised beds

Organic matter2.5%moderate

Hydrologic groupC/Dslow when drained; wet otherwise

Farmland classprime farmlandUSDA classification

Map unit: Dennis silt loam, 1 to 3 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 74055; soils change within a few hundred feet, so a home soil test (pH, nutrients) is still the best guide.

Climate in Owasso, OK

Summer high94 °Faverage high, July

Winter low28 °Faverage low, January

Hot days74days a year at 90 °F or more

Freezing nights72nights a year at 32 °F or less

Growing degree days5,332base 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

Precipitation43.1 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: Tulsa Intl Airport, OK (7 mi away); precipitation: Owasso 1.8 Se, OK (within 1 mile). Daylight is calculated from latitude.

Nearby ZIP codes

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

Collinsville, OK · 7 mi

Oklahoma planting zones →

Questions about 74055

What planting zone is ZIP code 74055?

ZIP code 74055 (Owasso, 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 Owasso, OK?

The median last spring frost (32 °F) near 74055 is March 31; after April 15 there is only a 10% chance of frost. Data: NOAA 1991–2020 normals, Tulsa Intl Airport station.

When is the first frost in Owasso, OK?

The median first fall frost near 74055 is November 4, giving a median frost-free growing season of 220 days.

When should I plant tomatoes in 74055?

Start tomato seeds indoors around Feb 3 – Feb 17 and set transplants outside around Apr 7 – Apr 21, one to three weeks after the median last frost.

How much rain and snow does 74055 get?

About 43.1 inches of precipitation a year (NOAA 1991–2020 normals, Owasso 1.8 Se station).

How hot do summers get in Owasso, OK?

The average high peaks at 94 °F in July, with about 74 days a year at 90 °F or more.

What kind of soil does 74055 have?

The USDA soil survey maps Dennis at the center of ZIP 74055: silt loam, somewhat poorly drained, pH about 5.6 (moderately acidic).

Did spring come early in Owasso, OK in 2026?

Spring leaf-out near 74055 came on Feb 12 in 2026, 15 days earlier than the 1991–2020 average (Feb 27), according to the USA National Phenology Network Spring Index.

What kind of onions grow in Owasso, OK?

Intermediate onions: the longest day near 74055 is 14 h 38 min, so day-neutral types bulb best; long-day varieties may not bulb fully.

Did the zone for 74055 change?

Yes. The 2012 USDA map put 74055 in zone 7a; the 2023 map puts it in zone 7b. The newer map uses 1991–2020 data and more weather stations.