The Columbia Gorge spans USDA hardiness zones 7a-7b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
A river canyon cut through the Cascades where wet marine air gives way to high desert in forty miles — pear, cherry, and apple orchards at the west end, vineyards and dryland ground at the east. Among the crops suited to this profile: kale, potato, douglas fir, and garlic. The site-level story — soil, sun, drainage — decides the rest.
The Columbia Gorge spans Oregon and Washington.
Your yard isn't all of the Columbia Gorge.
The Columbia Gorge spans USDA zones 7a-7b, but your parcel sits in exactly one — and slope, tree cover, and low spots nudge it further. 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 Columbia Gorge — soil, climate, flood, and parcel records. How we handle your address.
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The Columbia Gorge — the short answer
The Columbia Gorge: USDA zones 7a-7b, 168–212 frost-free days depending where in it you stand, across 2 states.
- USDA zones
- 7a-7b
- USDA PHZM 2023, aggregated over the footprint
- Shortest season here
- 168 days
- NOAA Regional Climate Centers ACIS, 1991-2020 — Klickitat County
- Counties
- 4
- US Census TIGER/Line 2025
- Region type
- County cluster
- Growable Ground growing-region registry
Region boundary: Growable Ground growing-region registry — curated county clusters, EPA Level III ecoregions, and town clusters drawn finer than any county. The season figure is this region's own record, measured across its 4 member counties, not a state or national average.
Hardiness Zone Range
The Columbia Gorge is not one growing season
One answer for the Columbia Gorge averages 4 counties whose growing seasons are 44 days apart — from 168 frost-free days in Klickitat County to 212 in Hood River County. That is the same region, measured the same way, in the same years. Which end of it your land sits nearer decides what finishes before the first hard freeze.
The middle half of 4 counties runs 193–207 days, with a median of 203 days — a 44-day span end to end.
Measured across 4 member counties, each carrying its own 28°F normal. NOAA Regional Climate Centers ACIS, 1991-2020. A member with no own record is absent from the range rather than counted as zero — nothing here is interpolated to the region. Your own site sits somewhere inside this range; a parcel report resolves where.
Where the line runs inside the Columbia Gorge
The middle half of the Columbia Gorge runs 193–207 frost-free days, and 2 of its 4 counties sit outside that — 1 on the short side, 1 on the long. A regional planting date describes the middle well and the ends poorly, which is worth knowing before you follow one.
Under 193 frost-free days
1 county
- Klickitat County · 168 days
The end of the region that sets the planting calendar — start seed indoors here and the season stretches to meet the crop.
193–207 frost-free days
2 counties
0 of 2 shown
The middle half of the region, and the part a single regional season describes well.
Over 207 frost-free days
1 county
- Hood River County · 212 days
Long enough for a second succession of a quick crop after the first comes out.
Each county is placed by its OWN 28°F frost-free normal (NOAA Regional Climate Centers ACIS, 1991-2020), the same figure its own guide page publishes. Elevation, slope and cold-air drainage move a site within its county as well — which is the part only your address resolves.
What Grows in the Columbia Gorge
Plants matched to the Columbia Gorge's USDA zones 7a-7b, ordered by how much hardiness margin each has across the region — the ones with room to spare at both ends of this band lead. Each links to its full growing profile.
Native Plants of the Columbia Gorge
Plants the USDA PLANTS Database documents as native and present in all 2 states this region crosses, kept only where the published hardiness range meets the Columbia Gorge’s USDA zones 7a-7b — closest range match first. Presence is recorded by state, so a plant can be documented across the state and still be scarce in your corner of the region.
The ground across the Columbia Gorge
The USDA soil survey maps this ground county by county. These are those records weighted by land area across four member counties — this region’s own profile, not a state figure.
The ground is predominantly Mollisols, at 48% of mapped acres, followed by Inceptisols (20%), Andisols (16%) and Alfisols (9%). Ten soil orders appear somewhere inside the footprint, which is the honest reason a regional soil answer only goes so far. The most extensive named soils are Bakeoven, Lickskillet, and Condon.
87% of those acres are well drained, and another 4% somewhat excessively drained, 2% moderately well drained. Topsoil pH runs 5.6–7.0 between the lowest and the highest county on record. 5% of the footprint is classed prime farmland.
Soil order
Mollisols
Drainage
Well drained
Topsoil pH
5.6–7.0
Hydric soils
1%
Soil changes across a driveway, so which of these your own ground sits on is a parcel question rather than a regional one. Klickitat County holds the most wetland ground here, at 2% — soil types explained.
USDA NRCS SSURGO via Soil Data Access
What this means for growing in the Columbia Gorge
The soil survey reads this ground county by county, and the readings above are those records summed across the Columbia Gorge. Here is what they mean for a garden here — and the move an experienced grower makes about each one.
Drainage
From county records87% of the mapped acres across the Columbia Gorge are well drained — ground that drains quickly. That is area-weighted across all four of its mapped counties.
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
From county recordsTopsoil across the Columbia Gorge runs pH 5.6–7.0 — near neutral in three of its four counties.
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
Safe to Grow Here?
What the federal record shows across the Columbia Gorge — and how to grow with it.
Across the Columbia Gorge's 4 counties the federal record holds 680 documented sites, mostly Underground Storage Tanks (404), Mining (94) and Brownfields (88). The heaviest single county is Wasco County, with 206.
That is a regional count, not a reading of any one lot — proximity to a documented site is information, not a diagnosis. Open the map outlined to the Columbia Gorge to see which records sit where you actually grow.
Sources Checked
Summed across the 4 counties in the Columbia Gorge
A note from Gnorman
What an experienced grower watches for around here
In and around the Columbia Gorge, two things run higher than the national average across the 4 counties in the Columbia Gorge — Mining (94 sites) and Superfund (11 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Mining: Mining sites — both historic and active — can leach heavy metals (arsenic, lead, cadmium, mercury) into soil and water for centuries after operations cease.
Superfund: Superfund sites represent the most severe contamination in the federal system.
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
Your land is one point inside the Columbia Gorge
Everything above resolves to the Columbia Gorge as a whole — a footprint whose own counties record seasons 44 days apart, and hardiness across zones 7a-7b. Your parcel sits at one point in that range, not in the middle of it. 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 region 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 regional average.
Your Lot vs the Columbia Gorge Average
Columbia Gorge Average
- ●USDA Zones 7a-7b, averaged across Columbia Gorge
- ●One soil character for all of Columbia Gorge
- ●State-average frost dates
YOUR Parcel
- ✓Your exact zone, not Columbia Gorge's 7a-7b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in the Columbia Gorge
Pull a site-specific report for your exact address in the Columbia Gorge — soil, sun, drainage, frost risk, contamination, and scored plant recommendations.
Three things about your lot that Columbia Gorge averages can't show:
We read public map data around The Columbia Gorge — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Columbia Gorge average
How we know this about the Columbia Gorge
The boundary: a cluster of neighboring counties. Growing regions have no official boundary, so this footprint is our published one, and every figure on this page was measured over the counties inside it rather than borrowed from the state around it.
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, aggregated across the footprint; the growing season from NOAA Regional Climate Centers ACIS 1991–2020 28°F normals, read at each member’s own record; boundaries from US Census TIGER/Line 2025; the contamination record from the federal sources named in that beat above; the soil from the USDA NRCS SSURGO survey, read at each member county’s own record and weighted to this footprint by land area. Where a member carries no record of its own, it is absent from the figure rather than filled in.
Common questions about the Columbia Gorge
What hardiness zone is the Columbia Gorge?
The Columbia Gorge spans USDA hardiness zones 7a-7b, aggregated from the USDA Agricultural Research Service Plant Hardiness Zone Map 2023 across the region's counties. Zones reflect average annual extreme minimum temperatures from 1991–2020 data.
How long is the growing season in the Columbia Gorge?
Measured between 28°F hard freezes, the Columbia Gorge's counties mostly run 193 to 207 frost-free days, median 203 (NOAA Regional Climate Centers ACIS, 1991–2020, over 4 member counties). That 14-day spread is the honest read — no single season describes 4 counties, and each county guide below carries its own.
When does frost risk end in the Columbia Gorge?
Across the Columbia Gorge, the middle half of member counties see their last 28°F hard freeze between Apr 12 and Apr 19 (median Apr 14), and their first fall freeze between Oct 26 and Nov 7. Those are hard freezes, not the last light frost: tender transplants wait for about May 5, and elevation decides which end of a 7-day spread you garden in.
What grows well in the Columbia Gorge?
The Columbia Gorge's conditions suit plants such as Kale, Potato, Douglas Fir, Garlic, Western Red Cedar, Hazelnut. What actually thrives on any one site still turns on its specific soil, sun, and drainage — we score each plant against the real conditions at your address.
How is the Columbia Gorge defined?
The Columbia Gorge is defined here as a curated cluster of 4 neighboring counties that share a growing character. Growing regions have no official boundary, so this footprint is our published one — every county in it is named on this page.
Which states does the Columbia Gorge cover?
The Columbia Gorge spans Oregon and Washington. Each state's full growing guide is linked on this page.
What other growing regions cover the same states?
Pacific Northwest, Columbia Basin, Willamette Valley, Oregon Coast (Maritime Cool-Summer Strip), Puget Sound Lowlands, and Inland Northwest (Northeast Washington) share at least one state with the Columbia Gorge. Growing regions overlap and interlock — a single address can sit inside more than one, which is why the precise read is always the parcel, not the region.
What this page reads at the Columbia Gorge’s own scale
6 of the readings below were taken at the Columbia Gorge's own scale — the zone 7a-7b band across its footprint, a median 203-day season across its 4 counties and 680 documented federal contamination records across its 4 counties, 206 of them in Wasco County alone; one is borrowed from a wider read, named and linked below.
Measured here
- The USDA hardiness band 7a-7b aggregated across all 4 counties in the footprintUSDA PHZM 2023
- The boundary itself — the 4 counties this region is curated fromGrowable Ground subregion registry
- The growing character that makes this region distinct from the states it crossesGrowable Ground subregion registry
- The 28°F season across the footprint — the middle half of its 4 counties run 193 to 207 frost-free days, median 203NOAA Regional Climate Centers ACIS, 1991-2020
- The federal contamination record over the whole footprint — 680 documented federal contamination records across its 4 counties, 206 of them in Wasco County aloneEPA, USGS and USDA federal site records
- The soil order mix across the footprint — 48% Mollisols, topsoil pH 5.6–7.0, area-weighted across its 4 mapped countiesUSDA NRCS SSURGO
Inherited from a wider read
- The candidate plant list — all 2 member states' curated sets, merged and filtered to zones 7a-7bfrom Oregon and Washington
What this page can’t tell you
- Which end of the 14-day range your ground sits at — 193 days at one extreme, 207 at the other, decided mostly by elevationfrost dates explained →
- Which of those soils your own ground sits on — the survey maps them county-wide, and they change across a drivewaysoil types explained →
- The soil pH, drainage, sun hours, and frost pockets on one specific lotwhy one lot differs from the next →
Explore the Columbia Gorge
State growing guides
Counties in this region
Other growing regions across Oregon and Washington
The maritime Northwest west of the Cascade crest — mild, wet winters and dry summers behind berries, tree fruit, and lush cool-season gardens. (Union of the west-side ecoregions.)
A dry basalt plateau of loess soils in the inland Northwest where irrigation turns arid ground into apple, cherry, hop, and wine-grape country.
Oregon's broad maritime valley pairs deep alluvial soils with cool wet winters and dry summers — the heart of the state's hazelnut, berry, and Pinot country.
Unlike the inland Willamette Valley captured by the broad Pacific Northwest region, the Oregon coast runs the opposite constraint: persistent marine fog holds summer heat so low that tomatoes, peppers, melons, and sweet corn rarely ripen — yet the same maritime air delivers a 263–308-day frost-free season (per county_data.json) where brassicas, greens, and other cool-season crops thrive nearly year-round. Curry County's south-coast banana belt around Brookings (zone 9b, the mildest winters in Oregon) anchors the U.S. Easter lily bulb district. Lead a coastal grower to plan for cool-season abundance and short-season or greenhouse strategies for heat-lovers — not the inland valley's frost-limited but heat-rich pattern.
The maritime lowland ringing Puget Sound — EPA's Puget Lowland ecoregion across Island, Kitsap, Mason, San Juan, and Thurston counties — where mild marine winters hold USDA zones 8a-9a and a long 227-to-300-day frost-free season.
The coldest, most continental corner of Washington. Spokane sits at USDA zone 6b, and the Colville and Selkirk highlands of Ferry and Pend Oreille counties drop to 6a — two to three zones colder than the state's maritime west side. Frost-free windows run just 167 to 202 days here, so the growing calendar leans on cold-hardy varieties, a later last-frost start, and a shorter tomato-and-pepper season than anywhere else mapped in Washington. This is NOAA's Northeastern Washington climate division (#9) — hot, dry summers and cold-snap winters across Spokane, Colville, Republic, and Newport.