The Okanogan Valley spans USDA hardiness zones 6b-7a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
The warm, rain-shadowed Okanogan River corridor running down from the Canadian border — premier tree-fruit ground with big summer days and valley-floor frost worth planning around. Well-matched crops include kale, potato, garlic, and western red cedar, and the gap between "grows in the area" and "grows in your yard" is closed by soil, sun, and drainage.
The Okanogan Valley spans Washington.
Your yard isn't all of the Okanogan Valley.
The Okanogan Valley spans USDA zones 6b-7a, 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 Okanogan Valley — soil, climate, flood, and parcel records. How we handle your address.
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The Okanogan Valley — the short answer
The Okanogan Valley: USDA zones 6b-7a, 203–225 frost-free days, in Washington.
- USDA zones
- 6b-7a
- USDA PHZM 2023, aggregated over the footprint
- Frost-free season
- 203–225 days
- NOAA Regional Climate Centers ACIS, 1991-2020
- Towns
- 5
- US Census TIGER/Line 2025
- Region type
- Town 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. Where a region publishes no measured season, no season figure is shown.
Hardiness Zone Range
What Grows in the Okanogan Valley
Plants matched to the Okanogan Valley's USDA zones 6b-7a, 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 Okanogan Valley
Plants the USDA PLANTS Database documents as native and present in this region’s state, kept only where the published hardiness range meets the Okanogan Valley’s USDA zones 6b-7a — 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 around the Okanogan Valley
The USDA soil survey maps this ground county by county. These are those records weighted by land area across the county containing the Okanogan Valley — the ground the Okanogan Valley sits in, read at the only grain the survey publishes.
In the county containing the Okanogan Valley, the ground is predominantly Mollisols, at 36% of mapped acres, followed by Inceptisols (34%), Andisols (22%) and Entisols (4%). Eight soil orders appear in that record, which is the honest reason a regional soil answer only goes so far. The most extensive named soils are Conconully, Nevine, and Myerscreek.
79% of those acres are well drained, and another 8% somewhat excessively drained, 2% excessively drained. Topsoil pH runs 6.3–6.8 in that county’s own record. 2% of the footprint is classed prime farmland.
Soil order
Mollisols
Drainage
Well drained
Topsoil pH
6.3–6.8
Hydric soils
2%
Soil changes across a driveway, so which of these your own ground sits on is a parcel question rather than a regional one. soil types explained.
USDA NRCS SSURGO via Soil Data Access
What this means for growing in the Okanogan Valley
The soil survey reads this ground county by county, and the readings above are the record for the county containing the Okanogan Valley. Here is what they mean for a garden here — and the move an experienced grower makes about each one.
Drainage
From county records79% of the mapped acres across the county containing the Okanogan Valley are well drained — ground that drains quickly. The survey maps this ground county-wide, so it describes the setting the Okanogan Valley sits in rather than the valley floor alone.
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 county containing the Okanogan Valley runs pH 6.3–6.8 — near neutral in the one record covering it.
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 Okanogan Valley — and how to grow with it.
Across Okanogan County, which contains the Okanogan Valley, the federal record holds 1,032 documented sites, mostly Mining (762), Underground Storage Tanks (152) and Nitrate (74).
That is the containing county's count — this region is a smaller piece of that ground, so it is context, not a reading of any one lot. Open the map outlined to the Okanogan Valley to see which records sit where you actually grow.
Sources Checked
Summed across the county containing the Okanogan Valley
A note from Gnorman
What an experienced grower watches for around here
In and around the Okanogan Valley, two things run higher than the national average across the county containing the Okanogan Valley — Mining (762 sites) and Superfund (16 sites). That's not a problem with your land — it's information about it.
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 Okanogan Valley
Everything above resolves to the Okanogan Valley as a whole — a footprint spanning USDA zones 6b-7a. Your parcel sits in exactly one of them. 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 Okanogan Valley Average
Okanogan Valley Average
- ●USDA Zones 6b-7a, averaged across Okanogan Valley
- ●One soil character for all of Okanogan Valley
- ●State-average frost dates
YOUR Parcel
- ✓Your exact zone, not Okanogan Valley's 6b-7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in the Okanogan Valley
Pull a site-specific report for your exact address in the Okanogan Valley — soil, sun, drainage, frost risk, contamination, and scored plant recommendations.
Three things about your lot that Okanogan Valley averages can't show:
We read public map data around The Okanogan Valley — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Okanogan Valley average
How we know this about the Okanogan Valley
The boundary: the region's own towns — a footprint finer than any county, because the county average would misread this microclimate. Growing regions have no official boundary, so this footprint is our published one, and every figure on this page was measured over the towns 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 Okanogan Valley
What hardiness zone is the Okanogan Valley?
The Okanogan Valley spans USDA hardiness zones 6b-7a, aggregated from the USDA Agricultural Research Service Plant Hardiness Zone Map 2023 across the region's own towns. Zones reflect average annual extreme minimum temperatures from 1991–2020 data.
How long is the growing season in the Okanogan Valley?
Measured between 28°F hard freezes, the Okanogan Valley's towns mostly run 204 to 206 frost-free days, median 204 (NOAA Regional Climate Centers ACIS, 1991–2020, over 5 member towns). That 2-day spread is the honest read — no single season describes 5 towns, and each town guide below carries its own.
When does frost risk end in the Okanogan Valley?
Across the Okanogan Valley, the middle half of member towns see their last 28°F hard freeze between Apr 1 and Apr 4 (median Apr 3), and their first fall freeze between Oct 24 and Oct 25. Those are hard freezes, not the last light frost: tender transplants wait for about Apr 24, and elevation decides which end of a 3-day spread you garden in.
What grows well in the Okanogan Valley?
The Okanogan Valley's conditions suit plants such as Kale, Potato, Garlic, Western Red Cedar, Apple, Cherry. 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 Okanogan Valley defined?
The Okanogan Valley is a true microclimate — smaller than the county that contains it, with a growing reality of its own. So this page is built from the region's own 5 towns, each carrying its own hardiness zone and frost record, rather than from a county average measured somewhere else.
Which states does the Okanogan Valley cover?
The Okanogan Valley spans Washington. Each state's full growing guide is linked on this page.
What other growing regions cover the same states?
Pacific Northwest, Columbia Basin, Puget Sound Lowlands, Columbia Gorge, Inland Northwest (Northeast Washington), and Olympic Peninsula share at least one state with the Okanogan Valley. 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 Okanogan Valley’s own scale
6 of the readings below were taken at the Okanogan Valley's own scale — the zone 6b-7a band across its footprint, a median 204-day season across its 5 towns and 1,032 documented federal contamination records across its one county, 1,032 of them in Okanogan County alone; one is borrowed from a wider read, named and linked below.
Measured here
- The USDA hardiness band 6b-7a aggregated across all 5 towns in the footprintUSDA PHZM 2023
- The boundary itself — the 5 towns 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 5 towns run 204 to 206 frost-free days, median 204NOAA Regional Climate Centers ACIS, 1991-2020
- The federal contamination record over the whole footprint — 1,032 documented federal contamination records across its one county, 1,032 of them in Okanogan County aloneEPA, USGS and USDA federal site records
- The soil order mix across the footprint — 36% Mollisols, topsoil pH 6.3–6.8, area-weighted across its one mapped countyUSDA NRCS SSURGO
Inherited from a wider read
- The candidate plant list — its state's curated sets, merged and filtered to zones 6b-7afrom Washington
What this page can’t tell you
- Which end of the 2-day range your ground sits at — 204 days at one extreme, 206 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 Okanogan Valley
State growing guides
Towns in this region
The county containing this region
Other growing regions across 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.
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.
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.
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.
The Olympic Peninsula grows in a maritime world of its own. Cooled and watered by the open Pacific and the Strait of Juan de Fuca, its four counties — Clallam, Jefferson, Grays Harbor, and Mason — hold one of the widest rainfall gradients in the contiguous U.S.: from the Hoh and Quinault temperate rainforests (140+ inches a year) to the Sequim–Dungeness rain shadow near 16 inches that made the valley North America's lavender country. Long, mild, cloud-tempered seasons (USDA zones 8a–8b) favor cool-season crops — brassicas, alliums, salad greens, hardy berries, and cider apples — over heat-lovers, and frost timing swings sharply as you climb from tidewater toward the Olympic Mountains (which is why Jefferson County reads a full zone cooler and shorter-seasoned than its coastal neighbors). This page reads the peninsula's own counties, not a Pacific-Northwest-wide average, so the season and zone figures reflect the coast you're actually standing on.