What Grows in Morrow County, Oregon

USDA Zones 7a · 1.3M acres

Morrow County, in Oregon, sits in USDA hardiness zone 7a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.

Well-matched crops include hazelnut, blueberry, grape (pinot noir), and kale, and the gap between "grows in the area" and "grows in your yard" is closed by soil, sun, and drainage.

Morrow County lies within the Columbia Basin — a regional growing area with its own character.

Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals

Score your parcel · free

Morrow County holds more than one microclimate.

Soils and elevations shift across Morrow County, so your frost dates and drainage aren't the county average. Enter your address and we'll score 1,112 plants against your land's actual soil, sun, and frost.

We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.

No card required · your full report in seconds

Quick Facts

USDA Zones

7a

Last Hard Freeze (28°F)

Mar 11

County normal — light frosts run a few weeks later

First Hard Freeze (28°F)

Nov 18

County normal — light frosts arrive a few weeks earlier

County Area

1.3M acres

Hardiness Zone Range

7a7a
3a (Cold)13b (Hot)

Zone maps are averages across Morrow County. Your yard's slope, trees, and frost pockets shift what actually grows — see your land's exact reading.

Soil in Morrow County

Across Morrow County, the ground is predominantly Mollisols, where Ritzville, Valby, and Quincy are the most extensive named soil series. The soil is generally well drained with a silt loam surface. Topsoil pH runs about 6.5–7.2, neutral. Rainfall drains through hydrologic group C soils.

Soil order

Mollisols

Drainage

Well drained

Prime farmland

0%

Hydric soils

0%

Soil still varies lot by lot — soil types explained.

Is it too late to plant in Morrow County?

Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. Cool-season crops can go in from around Feb 11; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 11 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 18 — long-season crops need about 90 days of runway, quick greens only 30. With a season this long, “too late” mostly means “switch crops” — second sowings and a full fall garden are the norm, with garlic closing the year.

Growing Challenges in Oregon

What an experienced grower plans around here — each one has a move.

West side: excessive rain and overcast skies reduce sun for warm-season crops

Map your sun honestly — a south-facing bed against a light wall recovers a surprising amount of the light the clouds take.

East side: arid conditions (8-15 inches rainfall) require irrigation

East of the Cascades, drip irrigation is infrastructure, not an accessory — plan it before the first planting.

Slug pressure is extreme in western Oregon

Evening patrols, iron-phosphate baits, and dry mulch edges knock slugs back — your extension guide covers the full toolkit.

Mountain areas have very short seasons (60-90 frost-free days)

At 60-90 frost-free days, season extension is the difference between a garden and a gamble — a high tunnel changes the math.

For cultivar selection, pest pressure, and planting-time guidance specific to Oregon, the OSU Extension Service is the authoritative local source.

Safe to Grow Here?

What the federal record shows across Morrow County — and how to grow with it.

Federal record: High

We checked the federal record across Morrow County121 documented sites across 7 of the 9 source types we track.

The most significant on record: 3 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.

Morrow County carries one of the heavier federal records we track — and that's not a verdict on your yard. Proximity to a documented site is information, not a diagnosis: nothing here says any particular parcel is affected. It does earn one concrete step — before food beds go in the ground, a professional soil test tells you exactly what you're working with, and raised beds with clean imported soil grow well almost anywhere in the meantime.

Sources: EPA, USGS1.8M documented sites tracked nationwide across 9 federal source types.

Environmental Intelligence

Understanding what's nearby helps you make informed decisions about where and how to grow.

Total Sites

121

across Morrow County

Risk Level

High

Highest-severity

3 Superfund sites

Severity Distribution

across Morrow County

High3Moderate33Low85

Highest-Severity Sites

Boardman Air Force Range
Superfund · Superfund (Non-NPL)
Boardman Bombing Range
Superfund · Superfund (Non-NPL)
Umatilla Army Depot (Lagoons)
Superfund · Superfund NPL
01S/24E-03CDB
Nitrate Monitoring · Well
01S/24E-03CDB
Nitrate Monitoring · Well

A note from Gnorman

What an experienced grower watches for around here

In and around Morrow County, two things run higher than the national average — CAFO (3 sites) and Toxic Release Inventory (15 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.

CAFO: CAFOs pose a different contamination profile than chemical sources.

Toxic Release Inventory: TRI facilities report annual chemical releases to air, water, and land.

Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.

Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.

Free Report

Check your specific parcel in Morrow County

Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,112 plant recommendations.

Three things about your exact spot that zone averages miss:

Your soil pHYour frost-free daysYour sun & shade

We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.

25+ data sources analyzed in seconds

Your Specific Parcel Matters

Morrow County Average

  • USDA Zones 7a
  • Generic soil type for the area
  • State-average frost dates

YOUR Parcel

  • Your exact hardiness zone
  • Your SSURGO soil type & pH
  • Your sun exposure, cast in 3D

See MY Growing Report

Free Report

Read your parcel in Morrow County

Pull a site-specific report for your exact address in Morrow County, Oregon — soil, sun, drainage, frost risk, and scored plant recommendations.

Three things about your exact spot that zone averages miss:

Your soil pHYour frost-free daysYour sun & shade

We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.

25+ data sources analyzed in seconds

Key Growing Facts for Morrow County, Oregon

  • USDA Hardiness Zones: 7a (USDA PHZM 2023)
  • Last Hard Freeze (28°F): Mar 11 (county normal, NOAA 1991–2020 Climate Normals — light frosts can follow for a few weeks)
  • First Hard Freeze (28°F): Nov 18 (county normal, NOAA 1991–2020 Climate Normals — light frosts can arrive a few weeks earlier)
  • Days Between Hard Freezes: ~252 (county normal, NOAA 1991–2020 Climate Normals)
  • County Land Area: 1.3M acres (US Census TIGER 2025)

Zone data: USDA ARS Plant Hardiness Zone Map 2023. Climate data: NOAA NCEI. County boundaries: US Census TIGER/Line 2025.

Frost dates here are the Morrow County average. Low spots and tree cover move them by days on any one yard — see your exact frost windows.

Frequently Asked Questions

What hardiness zone is Morrow County, Oregon?

Morrow County sits in USDA hardiness zone 7a, per the USDA Plant Hardiness Zone Map 2023. Zones reflect average annual extreme minimum temperatures from 1991–2020 weather data.

Is it too late to plant in Morrow County?

Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. Cool-season crops can go in from around Feb 11; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 11 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 18 — long-season crops need about 90 days of runway, quick greens only 30. With a season this long, “too late” mostly means “switch crops” — second sowings and a full fall garden are the norm, with garlic closing the year.

When does frost risk typically end in Morrow County?

The last hard freeze (28°F) in Morrow County typically lands around Mar 11, per NOAA 1991–2020 climate normals — an earlier marker than the light-frost dates many planting charts quote. That marks the hard freeze, not the last light frost — light frosts can still bite for a few more weeks, so tender transplants usually wait another 2–3 weeks.

How long is the growing season in Morrow County?

Measured between 28°F hard freezes, Morrow County sees about 252 frost-free days — roughly Mar 11 through Nov 18, per NOAA 1991–2020 climate normals. Tender crops get a somewhat shorter practical window, since lighter frosts reach a few weeks past the hard-freeze dates on both ends.

What vegetables grow in Morrow County?

Morrow County's zone 7a supports a wide range — strong performers include Hazelnut, Blueberry, Grape (Pinot Noir), Kale, and Hop. What actually takes on any one site comes down to its soil, sun, and drainage, and we score each plant against the real conditions at your address.

Which hardiness zone is Morrow County, really?

Officially, Morrow County sits in USDA zone 7a (USDA PHZM 2023) — but a zone is a 30-year average of winter's coldest night across an area, and it can't see any one yard. A south-facing slope, a tree line, or a low frost pocket can shift a single site by half a zone either way, which is why neighboring gardeners often quote different numbers. We read the conditions at your exact address — soil, sun, slope, and frost — and score 1,112 plants against what's actually there.

Is the soil safe to grow vegetables in Morrow County?

The federal record around Morrow County runs heavier than most — 121 documented sites — so test the soil before planting food in the ground, and raised beds with clean imported soil grow well in the meantime. Even here, proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what's recorded and where.

Just moved to Morrow County — what should I know before planting?

Start with three facts. Morrow County sits in USDA zone 7a, which sets what survives winter; the last 28°F hard freeze typically clears around Mar 11, with about 252 frost-free days to work with (NOAA 1991–2020 climate normals); and 121 documented sites sit on the federal record here, so a soil test before food beds is the smart first step. From there, matching plants to your actual soil and sun is the fun part.

Everything on this page is a Morrow County average. Your yard writes its own version — we read soil, sun, drainage, and frost at your exact address. Try it for 14 days — no card required.

Will It Grow Here?

Zone fit is the first question — each answer below reads Oregon's frost window, season length, and soil profile against the plant's real requirements.