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 cabbage, pawpaw, california poppy, and collard greens, 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
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 1,086 plants against your land's actual soil, sun, and frost.
We read public map data around Morrow County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Morrow County — the short answer
Morrow County, Oregon: USDA zone 7a, about 208 days between hard freezes, across 1.3M acres.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 5
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 30
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~208
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 1.3M acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are county 28°F normals: light frosts run a few weeks past them, and tender transplants usually wait 2–3 weeks after the last hard freeze.
Hardiness Zone Range
Zone 7a is Morrow County's average, not your lot's — a low corner or a tree line moves it. Against Morrow County's 208-day season, see what your own ground reads.
Heat in Morrow County
Across a year, Morrow County accumulates about 2,118 growing degree days above 50°F, about 266 more than the middle Oregon county — ahead of 26 of Oregon’s 36 counties. Degree days are the heat a crop actually gets to work with — more of them is more room to ripen a long-season crop before the freeze closes the window.
Grounded in PRISM Climate Group, Oregon State University — 1991–2020 monthly normals
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.
How the ground varies across Morrow County
The USDA soil survey maps 90% of Morrow County as well drained — but another 10% drains differently: 7% excessively drained, 3% somewhat excessively drained.
Ritzville is the most extensive named soil at 8% of mapped acres, then Valby (6%) and Quincy (6%).
Which of them your own lot sits on is a parcel question, not a county one. Check your address for the survey at your boundary.
What this means for growing in Morrow County
Each reading below is measured for Morrow County itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Drainage
MeasuredThe dominant soils across Morrow County are well drained, in hydrologic group C — ground that drains quickly.
The upside is soil you can work early in spring and roots that never drown; the cost is that fast-draining ground dries out fast and leaches nutrients away before plants can use them.
Work in compost and mulch to hold moisture and feed, and water more often in short doses than deep and rarely.
USDA NRCS SSURGO
Surface pH
MeasuredTopsoil across Morrow County runs about pH 6.5–7.2, close to neutral.
This is the range most vegetables prefer — one correction you probably do not have to make, which is genuinely good news for a new bed.
Keep it there with compost rather than lime or sulfur, and only amend if your own soil test says otherwise.
USDA NRCS SSURGO
Season length
MeasuredMorrow County runs about 208 days between hard freezes — a long growing season.
There is slack for succession plantings and slow-finishing crops: many vegetables can be sown twice, and the heat-lovers have time to ripen fully.
Plan a second sowing of quick crops after the first comes out, and use the fall window most gardeners let sit idle.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredMorrow County sits in USDA hardiness zone 7a.
The zone sets which perennials, shrubs, and fruit trees live through an average winter here — a plant rated for a colder zone is a safe bet, one rated warmer needs winter protection or gets treated as an annual.
Match perennials and fruit to the zone before you buy, so nothing you plant is a gamble against the cold.
USDA PHZM 2023
The kind of country Morrow County is in
Morrow County spans 2 EPA Level III ecoregions — Columbia Plateau (81%) and Blue Mountains (19%). Which one your land falls in changes what grows wild there and how the ground behaves, and a county-wide answer cannot tell you which.
What Grows in Morrow County
We scored all 1,086 plants against Morrow County's own USDA zone 7a and its own 208-day season between hard freezes, using the same matching engine that runs a full parcel report. These cleared both. Sun, soil pH and drainage vary lot by lot — those are the parcel questions below. Each card opens that plant's Oregon profile.
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 Mar 8; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 5 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 30 — 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.
Documented around Morrow County
- monarch butterfly23 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Morrow County
USGS estimates 199,052 lb of Glyphosate on Morrow County farmland in 2019, its largest by weight, ahead of Atrazine (43,783 lb) and 2,4-d (22,484 lb).
Farmland across the whole county, not any one lot. Check your address for the site-by-site record.
Safe to Grow Here?
What the federal record shows across Morrow County — and how to grow with it.
We checked the federal record across Morrow County — 121 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.
There's a meaningful federal record across Morrow County — worth a look before you plant food, not a reason to hold back from growing. Proximity to a documented site is information, not a diagnosis of any one yard. A soil test before new food beds is the sensible precaution here, and the map shows exactly which sites sit where, so you can see what's actually near you.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near Morrow County
Closest first, across Morrow County. Listing isn't leaking, and distance isn't exposure.
- MORROW COUNTY ROAD DEPT - LEXINGTONUnderground Storage Tanks · 2.7 mi
- KINZUA RESOURCES / HEPPNER POWER PLANT SITEToxics Release Inventory · 3.5 mi
- KINZUA CORPORATIONUnderground Storage Tanks · 3.5 mi
- USWEST - LEXINGTON C O - 010150Underground Storage Tanks · 4.2 mi
- LEXINGTON SERVICEUnderground Storage Tanks · 4.2 mi
- LEXINGTON AIRPORT - MORROW CO DEPTUnderground Storage Tanks · 4.3 mi
- GAR AVIATIONUnderground Storage Tanks · 4.3 mi
- OR STATE HWY, 5-12 HEPPNERUnderground Storage Tanks · 5.0 mi
- MILLER & SONS WELDINGUnderground Storage Tanks · 5.0 mi
- VERNS SPORTSUnderground Storage Tanks · 5.0 mi
- COLUMBIA BASIN ELECTRIC CO-OP INCUnderground Storage Tanks · 5.1 mi
- HEPPNER SHELLUnderground Storage Tanks · 5.3 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Morrow County's center, not your beds. Run your own address for what's upwind of you specifically.
Environmental Intelligence
The counts behind that headline — every source type on the record near Morrow County.
Sources Checked
across Morrow County
Severity Distribution
across Morrow County
Highest-Severity Sites
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 across Morrow County — CAFO (3 sites) and Toxics 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.
Toxics 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.
Check your specific parcel in Morrow County
Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,086 plant recommendations.
25+ data sources read at your address, not the Morrow County average
Your land is one point inside Morrow County
Everything above resolves to Morrow County as a whole — one PHZM band and one county frost record, read across 1.3M acres. Your parcel is one point inside that footprint. Slope, tree cover, a low spot that pools cold air, and what is in the soil are all resolved at the address, and none of them are visible at county scale. That is the honest boundary of this page, and the reason the next step is a reading of your own ground rather than a better county average.
Your Lot vs the Morrow County Average
Morrow County Average
- ●USDA Zones 7a, averaged across Morrow County
- ●One soil character for all of Morrow County
- ●Frost dates read at Morrow County's scale: Apr 5 to Oct 30
YOUR Parcel
- ✓Your exact zone, not Morrow County's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing 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 lot that Morrow County averages can't show:
We read public map data around Morrow County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Morrow County average
How we know this about Morrow County
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at county grain; hard-freeze dates from NOAA 1991–2020 28°F normals at this county’s own record where one resolves, and the labelled statewide window where none does; soils from the USDA NRCS SSURGO survey, area-weighted across the county’s own map units; boundaries and acreage from US Census TIGER/Line 2025; the contamination and pesticide records from the federal sources named in their beats above. Where Morrow County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Morrow County
When does frost risk typically end in Morrow County?
The last hard freeze (28°F) in Morrow County typically lands around Apr 5, per NOAA 1991–2020 climate normals — earlier than the light-frost dates most charts quote. That marks the hard freeze, not the last light frost — lighter frosts keep biting past it, which is why tender transplants here wait until about Apr 26.
How long is the growing season in Morrow County?
Measured between 28°F hard freezes, Morrow County sees about 208 frost-free days — roughly Apr 5 through Oct 30, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 26 to Oct 16, about 173 days.
Is the soil safe to grow vegetables in Morrow County?
The federal record around Morrow County is a meaningful one — 121 documented sites, mostly Underground Storage Tanks entries (75), the nearest Underground Storage Tanks record about 2.7 miles out — so a soil test before new food beds is a sensible precaution here, not a reason to hold back from growing. Remember that proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what sits where.
Everything above is measured at Morrow County's scale — its 7a band and its 208-day season. Your yard writes its own version of Morrow County's numbers: 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.
What this page reads at Morrow County’s own scale
9 of the readings below were taken at Morrow County's own scale — its own ~208-day span between 28°F freezes, the 3 most extensive soil series mapped here and 121 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Morrow County's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Morrow County's own 28°F hard-freeze dates and its ~208-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Morrow CountyUSDA NRCS SSURGO
- 121 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 2.7 miles outFederal environmental registers
- Morrow County's boundary and the 1,299,537 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~208-day seasonGrowable Ground crop-matching engine
- The 2 ecoregions Morrow County spans, Columbia Plateau the largestUS EPA Level III Ecoregions
- Open occurrence records documented in Morrow County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Morrow County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every Oregon grower plans around — written at state scale, so they stay on the state guidefrom Oregon
What this page can’t tell you
- How the season shifts across Morrow County — the ~208 days above is one reading at its centre; the 12 towns below each carry their owntowns in this county →
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Morrow County's 1,299,537 acreswhy one lot differs from the next →
- Which of those 121 documented sites actually reaches your soil — that needs your address, the wind, and the groundwater directionhow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — none of it survives being averaged over Morrow Countyread your own land →