Washington spans USDA hardiness zones 4a-9a, with a growing season of about 130 frost-free days — a season built for sprinters: quick vegetables, frost-tolerant greens, and fruit bred for hard winters.
The climate hand here is 6-90 inches of annual rainfall, a median of roughly 2,250 growing-degree days (base 50°F), and about 1,950 winter chill hours for tree fruit — the numbers that decide what ripens comfortably and what runs out of runway. On the soil map, volcanic ash, silt loam (Palouse), sandy loam, and glacial outwash dominate — and drainage is the trait that separates an easy bed from a project. Growing in Washington really means growing in one of its distinct regions — Pacific Northwest, Columbia Basin, and The Palouse — each with its own zone band and frost rhythm. These conditions suit apple, cherry, hop, and grape — a starting list any specific site will trim or extend with its own soil, sun, and drainage.
Grounded inUSDA PHZM 2023•NOAA Climate Normals•USDA NRCS SSURGO•GDD aggregate (Cornell CALS)•Chill-hour aggregate (MSU Extension)•USDA hardiness sub-region map•EPA FRS•USDA PLANTS•Growable Ground suitability scoring
Washington spans zones 4a-9a, but your yard sits in exactly one — and slope, tree cover, and low spots nudge it further. 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.
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Distinct growing regions within Washington — each has its own zones, soils, and signature crops.
USDA Zones
4a-9a
USDA PHZM 2023
Last Frost
Mar 1 - Jun 1
NOAA 30-yr Normals
First Frost
Sep 15 - Nov 15
NOAA 30-yr Normals
Annual Rainfall
6-90 inches
NOAA Climate Normals
Zone maps are averages across Washington. Your yard's slope, trees, and frost pockets shift what actually grows — see your land's exact reading.
The soil types that dominate Washington — how each drains decides more about crop success than almost anything else. Tap any soil to learn what it is and how to work with it.
Drainage
Excellent and unusual: ash soils drain freely yet hold remarkable amounts of plant-available water in their porous structure — the best of both habits.
What thrives
Volcanic regions grow celebrated crops the world over: orchards, berries, vegetables, coffee, and wine grapes all prosper on ash-derived soils.
Drainage
Moderate. Silt holds water well and releases it steadily, though the fine particles can crust after hard rain and compact under traffic.
What thrives
The full vegetable garden does well here, and small grains, corn, and leafy greens are classic silt-loam crops. Its steady moisture suits shallow-rooted plants that dislike drought stress.
Drainage
Fast. The sand fraction opens the soil up, so water moves through the root zone quickly and the surface rarely stays soggy. The trade is that nutrients ride out with the water.
What thrives
Root crops love it — carrots, potatoes, radishes, and onions size up cleanly in ground they can push through. Melons, sweet potatoes, asparagus, and most herbs appreciate the warmth and the drainage.
Drainage
Fast and deep. Outwash plains are among the best-drained ground in the glaciated states.
What thrives
Root crops, asparagus, bush fruits, and orchard trees on drought-tolerant rootstocks. Anything that resents wet feet considers outwash a gift.
Drainage
Usually good: rivers sort their loads, and most alluvial soils have enough sand and silt to move water while holding plenty for roots. Low-lying pockets can run wet.
What thrives
Nearly everything — vegetables, orchards, vines, and berries all prosper on alluvium. Its depth lets roots go as far down as they care to.
Soil data: USDA NRCS SSURGO · Soil types explained
Plants well-suited to Washington's climate, soils, and growing season — each links to its full growing profile.
For most of the year, no — what changes is which crops still fit the days remaining. Across Washington, cool-season planting typically opens about four weeks before the local last hard freeze — county medians put that freeze near Mar 24, with the middle half of counties between Mar 13 and Apr 5 (NOAA 1991–2020 climate normals). Tender transplants wait two to three weeks past it, and fall planting counts back from first freezes mostly between Oct 29 and Nov 21 — long-season crops need about 90 days of runway, quick greens only 30. A long window like this one runs successions deep into fall — and even its last weeks take quick greens and garlic.
The plants Washington put its name on — cultural emblems, not growing recommendations.
Coast rhododendron
Rhododendron macrophyllum
Designated 1892.
Western hemlock
Tsuga heterophylla
Designated 1947.
Walla Walla sweet onion
Designated 2007.
Plants the USDA PLANTS Database documents as native and present in Washington — a real per-state range, not just a zone match. Presence is statewide, so a plant may still be uncommon in your specific county; your state’s Cooperative Extension or a native-plant society is the local authority.
US-native plants whose hardiness range overlaps Washington’s USDA zones 4a-9a but which USDA PLANTS doesn’t map to a single state range here. Zone overlap is a starting filter, not a range map.
What an experienced grower plans around here — each one has a move.
Extreme rain divide: 90+ inches west, 6 inches east of Cascades
Plant to your side of the Cascades, not to the state — your exact spot's rainfall decides the whole plan.
East side requires irrigation — no rain from June through September
With no summer rain, drip lines and deep mulch are the growing season — set them up before June.
Slug and root rot pressure on the wet west side
Raise the beds, bait the slugs, and water mornings only — the wet-side trio that keeps roots and leaves healthy; extension has the details.
Short seasons at elevation in the Cascades and northeast corners
In the short-season corners, fast varieties plus a cold frame or tunnel reliably close the gap.
For cultivar selection, pest pressure, and planting-time guidance specific to Washington, the WSU Extension is the authoritative local source.
Safe to Grow Here?What the federal record shows across Washington — and how to grow with it.
We checked the federal record across Washington — 33,912 documented sites across 8 of the 9 source types we track.
The most significant on record: 329 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Washington 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.
Severity Distribution
across Washington
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Washington, Mining runs higher than the national average — 3,881 sites nearby. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around 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.
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
State averages sketch the shape. Your soil, sun exposure, drainage, and microclimate decide what actually takes. Pull a site-specific report for your exact parcel.
Enter your address. We read your soil, sun, drainage, and frost dates, then score 1,112 plants against the real conditions on your land.
Three things about your exact spot that zone averages miss:
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
Washington spans USDA hardiness zones 4a-9a, per the USDA Plant Hardiness Zone Map 2023. Zones reflect average annual extreme minimum temperatures from 1991–2020 weather data.
For most of the year, no — what changes is which crops still fit the days remaining. Across Washington, cool-season planting typically opens about four weeks before the local last hard freeze — county medians put that freeze near Mar 24, with the middle half of counties between Mar 13 and Apr 5 (NOAA 1991–2020 climate normals). Tender transplants wait two to three weeks past it, and fall planting counts back from first freezes mostly between Oct 29 and Nov 21 — long-season crops need about 90 days of runway, quick greens only 30. A long window like this one runs successions deep into fall — and even its last weeks take quick greens and garlic.
Across Washington, the middle half of counties see their last hard freeze (28°F) between about Mar 13 and Apr 5, with a county median near Mar 24 (NOAA 1991–2020 climate normals). 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.
Measured between 28°F hard freezes, growing seasons across Washington's counties mostly run about 205 to 254 days, with a county median near 229 (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.
Washington's zones 4a-9a support a wide range — strong performers include Apple, Cherry, Hop, Grape, and Blueberry. 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.
Officially, Washington spans USDA zones 4a-9a (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.
The federal record across Washington runs heavier than most — 33,912 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.
Start with three facts. Washington spans USDA zones 4a-9a, which sets what survives winter; last hard freezes range from about Mar 13 to Apr 5 across its counties (NOAA 1991–2020 climate normals); and 33,912 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 Washington 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.
Explore growing conditions by county — each has its own zone range and land area.
Explore growing conditions by city or town in Washington.
Washington shares its dominant growing region with these states — a useful comparison if you're weighing where a crop will behave the same way.
