Generally — Most Areas
Canada wild rye (zones 3-8) suits most of Washington (4a-9b) — zones 4-8 are in range, and the rest of the state is the exception.
Canada Wild Rye in Washington — the short answer
Canada Wild Rye in Washington: hardy in zones 3–8, full sun, against a state median of ~208 frost-free days.
- Plant zones
- 3-8
- Manual horticultural correction (source not retained); NC State Extension and Missouri Botanical Garden, with the remaining rows from other published sources or Growable Ground compilation
- Washington zones
- 4a-9b
- USDA PHZM 2023
- Frost window
- Mar 16 - Apr 15 – Oct 24 - Nov 18
- NOAA RCC ACIS 1991-2020, 28°F
- Shortest county season
- 131 days
- NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze
Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS and university Extension sources — per-field provenance varies and is published with the dataset.
Your yard isn't the whole zone.
Washington spans zones 4a-9b, but your yard sits in exactly one — and slope, tree cover, and cold-air pockets nudge it further. Enter your address and we'll score canada wild rye against your parcel's actual hardiness, soil, and sun.
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Washington is not one climate
Washington’s winter-low ladder runs across 39 counties, from zone 6 in Ferry County to zone 9 in San Juan County. That is 30°F between the two counties’ average coldest night — the difference between canada wild rye overwintering in the ground and coming under cover.
The middle half of 39 counties runs 7–8.5 zones, with a median of 7 zones — a 3-zone span end to end.
Measured across 39 Washington counties. USDA PHZM 2023, per county. Quartiles are order statistics — every figure shown is a value a real county recorded, not an interpolation. Your own site sits somewhere inside this range; a parcel report resolves where.
Where in Washington Fits Best
Canada Wild Rye is rated for zones 3–8 — a cold floor USDA puts at -40 to -30°F. Against Washington’s 39 counties that band holds in 26 of them, and the line runs at Ferry County (zone 6a), the coldest county still inside it.
Inside zones 3–8
26 counties
- Okanogan County · zone 6a
- Pend Oreille County · zone 6a
- Douglas County · zone 6b
3 of 26 shown
Above the zone 8 ceiling
13 counties
- Clallam County · zone 8b
- Clark County · zone 8b
- Cowlitz County · zone 8b
3 of 13 shown
Too little winter chill rather than too much cold — a low-chill selection is what changes it.
County hardiness zones: USDA Plant Hardiness Zone Map (PHZM) 2023, per county. A zone is a 10°F band of average annual extreme minimum temperature, so the floor above is the band the plant's rating denotes, not a single measured kill point. Slope, shelter and cold-air drainage routinely move a site half a zone either way from its county figure — which is the part only your address resolves.
Even within Washington's zones 4a-9b, county microclimates differ enough to change what thrives. These counties carry the closest zone match for canada wild rye (USDA PHZM 2023):
Zone Comparison
Canada Wild Rye Needs
- USDA Zones: 3-8
- Frost-Free Days: 90+
- Sun: Full Sun
- Mature size: 4 ft tall
- Drought tolerance: Medium
Washington Has
- USDA Zones: 4a-9b
- Last Hard Freeze (28°F): Mar 16 - Apr 15
- First Hard Freeze (28°F): Oct 24 - Nov 18
- Annual Rainfall: 6-90 inches
- Common Soils: Volcanic ash, Silt loam (Palouse), Sandy loam
Plant Zone Range (zones 3-8)
Preferred Soil pH
Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS, and university Extension sources — per-field provenance varies and is published with the dataset. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.
When to Plant Canada Wild Rye in Washington
The frost window
Across Washington, the last spring hard freeze (28°F) clears between Mar 16 and Apr 15, and the first fall hard freeze lands between Oct 24 and Nov 18 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 192-day window you can count on — up to 247 days on a mild site in a kind year. That marks the hard freeze, not the last light frost, so tender transplants usually wait another 2-3 weeks.
Winter standing
Washington runs as cold as USDA zone 4, and no sourced winter-hardiness floor is on record for canada wild rye, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether canada wild rye is a permanent planting or a replant-every-spring crop for you turns on your own zone within Washington; check its hardiness range against that before treating it as long-lived ground.
Frost window: NOAA Climate Normals 1991-2020. Plant timing fields: Growable Ground Plant Database — frost-free days from FAO ECOCROP, days to harvest from university Extension production guides, and growing-degree-day and chill-hour minimums that are compilation estimates rather than published figures. Your site's own frost dates can run earlier or later than the state range — a parcel report pins them down.
Growing Season Fit
The zone check says canada wild rye survives winter in part of Washington, not across all of it. Whether the season is long enough — and warm enough — is a different question.
Frost-free days
Canada Wild Rye wants 90+ frost-free days; a typical Washington site sees ~208 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves comfortable headroom for succession planting.
GDD and chill-hour figures are computed from PRISM 1991-2020 monthly climate normals; frost-free days from NOAA Regional Climate Centers ACIS, 1991-2020. Each is the state median across its counties (P25/P75 span the within-state spread). Hardiness-zone range is USDA PHZM 2023.
Soil + Drainage Fit
Canada Wild Rye tolerates a wide pH range (pH 5-8.2) — 3.2 units, acid ground through alkaline — so soil acidity is rarely what limits it in Washington. A soil test is still worth having, but for what else it tells you about this site, not to clear this plant. It will grow across that whole span, but it does best between pH 5.5 and 6.5 — worth knowing before you decide whether a Washington soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells), excessive (dry/moderately dry). If your Washington site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.
Plant pH requirements: FAO ECOCROP and USDA PLANTS, with the remaining rows from other published sources or Growable Ground compilation. Drainage: FAO ECOCROP, with the remaining rows from other published sources or Growable Ground compilation. Washington soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
What Else to Consider for Canada Wild Rye in Washington
Zone compatibility tells you about winter cold survival — but Washington growers also need to think about:
Extreme rain divide: 90+ inches west, 6 inches east of Cascades
East side requires irrigation — no rain from June through September
Slug and root rot pressure on the wet west side
Short seasons at elevation in the Cascades and northeast corners
What to actually do about these — and the constraints that apply to every Washington grower, not just canada wild rye — is covered on the Washington growing guide.
Timing shifts within Washington
Canada Wild Rye needs about 90 days of frost-free season to complete its cycle. Even Whatcom County — Washington’s shortest season at 131 frost-free days — clears that by 41 days, so season length isn’t the constraint anywhere in Washington. What varies is your own parcel.
Across Washington’s 39 counties the frost-free season runs from 131 days in Whatcom County to 300 days in San Juan County — a spread of 169 days, which is why a single statewide planting date misleads. The median Washington county sees 208 frost-free days, leaving canada wild rye about 118 days of slack on a typical parcel — room for a second sowing where the season runs long.
County last-freeze dates and frost-free day counts: NOAA Regional Climate Centers ACIS (1991-2020), county 28°F freeze (earlier than the folk 32°F "last frost"). Canada Wild Rye's 90-day requirement: USDA PLANTS / Growable Ground plant database (minimum frost-free days). A parcel report resolves your address's own frost dates.
Washington Cooperative Extension
For Washington-specific cultivar recommendations, planting calendars, and pest pressure for canada wild rye, the canonical source is WSU Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Canada Wild Rye native to Washington?
Yes — the USDA PLANTS Database (accessed 2026-07-01) documents Canada Wild Rye as native to Washington. Planting it supports the pollinators and wildlife that evolved alongside it.
Native-range data: USDA PLANTS Database state-distribution records, accessed 2026-07-01.
Common Questions About Growing Canada Wild Rye in Washington
When can I plant Canada Wild Rye in Washington?
Washington's last spring hard freeze (28°F) clears between Mar 16 and Apr 15, and the first fall hard freeze lands between Oct 24 and Nov 18 (NOAA Regional Climate Centers ACIS, 1991-2020). No sourced winter-hardiness floor is on record for Canada Wild Rye, so this page does not state whether it overwinters in Washington and publishes no fall establishment date for it — check its hardiness range against your own zone before treating it as a permanent planting.
What hardiness zone is Canada Wild Rye grown in across Washington?
Washington spans USDA hardiness zones 4a-9b (USDA ARS PHZM 2023). Canada Wild Rye carries a range of zones 3-8, so the overlap zones are where outdoor growing is most reliable.
How many frost-free days does a typical Washington site have?
A typical Washington site sees ~208 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Canada Wild Rye needs 90+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date.
Is Canada Wild Rye native to Washington?
Yes — the USDA PLANTS Database (accessed 2026-07-01) documents Canada Wild Rye as native to Washington. Planting it supports the pollinators and wildlife that evolved alongside it.
How should I amend the soil for Canada Wild Rye in Washington?
Canada Wild Rye tolerates pH 5-8.2 and well (dry spells), excessive (dry/moderately dry) drainage (FAO ECOCROP). That is a 3.2-unit span, acid ground through alkaline, so pH is rarely what limits this plant on a Washington site — amend for drainage and organic matter first.
Will Canada Wild Rye actually grow on my specific land in Washington?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores canada wild rye against your address's exact soil pH, drainage, sun, and frost-date data drawn from USDA SSURGO, NOAA, and PRISM — not state averages.
Check your specific parcel in Washington
State-level data is a sketch. Your Growable Ground report scores canada wild rye against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Washington canada wild rye averages can't show:
We read public map data around Washington — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Washington canada wild rye average
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