Generally — Most Areas
white spruce (zones 2-6) suits most of Alaska (1a-9a) — zones 2-6 are in range, and the rest of the state is the exception.
White Spruce in Alaska — the short answer
White Spruce in Alaska: hardy in zones 2–6, part sun, against a state median of ~147 frost-free days.
- Plant zones
- 2-6
- 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
- Alaska zones
- 1a-9a
- USDA PHZM 2023
- Frost window
- Apr 16 - May 15 – Sep 24 - Oct 29
- NOAA RCC ACIS 1991-2020, 28°F
- Shortest county season
- 85 days
- NOAA Regional Climate Centers ACIS station record, 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.
Alaska spans zones 1a-9a, 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 white spruce against your parcel's actual hardiness, soil, and sun.
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Alaska is not one climate
A single Alaska answer averages 28 counties whose growing seasons are 155 days apart — from 85 frost-free days in Southeast Fairbanks County to 240 in Sitka County. Which end of that your land sits nearer changes what white spruce can finish before the first hard freeze.
The middle half of 28 counties runs 118–196 days, with a median of 145 days — a 155-day span end to end.
Measured across 28 Alaska counties. NOAA Regional Climate Centers ACIS station record, 1991-2020, county 28°F killing freeze. 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 Alaska Fits Best
Even within Alaska's zones 1a-9a, county microclimates differ enough to change what thrives. These counties carry the closest zone match for white spruce (USDA PHZM 2023):
Zone Comparison
White Spruce Needs
- USDA Zones: 2-6
- Sun: Part Sun
- Mature size: 60 ft tall
- Drought tolerance: High
Alaska Has
- USDA Zones: 1a-9a
- Last Hard Freeze (28°F): Apr 16 - May 15
- First Hard Freeze (28°F): Sep 24 - Oct 29
- Annual Rainfall: 10-160 inches
- Common Soils: Permafrost, Glacial silt, Volcanic ash
Plant Zone Range (zones 2-6)
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 White Spruce in Alaska
The frost window
Across Alaska, the last spring hard freeze (28°F) clears between Apr 16 and May 15, and the first fall hard freeze lands between Sep 24 and Oct 29 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 132-day window you can count on — up to 196 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
Alaska runs as cold as USDA zone 1, and no sourced winter-hardiness floor is on record for white spruce, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether white spruce is a permanent planting or a replant-every-spring crop for you turns on your own zone within Alaska; 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.
Soil + Drainage Fit
White Spruce prefers acidic soil (pH 3.7-5.5). Alaska's permafrost can run on the acidic side, which often aligns well — confirm with a soil test before planting. It will grow across that whole span, but it does best between pH 4 and 5 — worth knowing before you decide whether a Alaska soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Alaska 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. Alaska soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
What Else to Consider for White Spruce in Alaska
Zone compatibility tells you about winter cold survival — but Alaska growers also need to think about:
Extremely short growing season (70-110 frost-free days)
Permafrost prevents deep root growth in many areas
Limited soil development in glacial terrain
What to actually do about these — and the constraints that apply to every Alaska grower, not just white spruce — is covered on the Alaska growing guide.
Where in Alaska White Spruce Is Zone-Hardy
White Spruce is rated for USDA zones 2–6. Every one of Alaska’s 30 counties sits inside that band — from Aleutians East County at zone 3a-4b to Yukon-Koyukuk County at zone 3a-4b — so winter cold is not what decides this plant anywhere in the state. What is left to vary is your own parcel: slope, shelter and cold-air drainage routinely move a site half a zone either way from the county figure.
Across those 30 counties Alaska’s winter-low ladder runs from zone 3a-4b in Aleutians East County to zone 3a-4b in Yukon-Koyukuk County — 1.5 USDA zones of spread, which is 15°F between the two counties’ average coldest night of the year. That is why a statewide hardiness answer is where you start and not where you finish.
The planting window moves with it. North Slope County holds its last hard freeze (28°F) until about Jun 7, while Sitka County is clear by Mar 24 — 75 days apart. Set white spruce out on your county’s date, not the state’s.
County hardiness zones: USDA Plant Hardiness Zone Map (PHZM) 2023, per county. County last-freeze dates: NOAA Regional Climate Centers ACIS (1991-2020), county 28°F killing freeze — earlier than the folk 32°F "last frost". White Spruce’s zone 2–6 band: USDA PLANTS / Growable Ground plant database. A parcel report resolves your address’s own zone and frost dates rather than its county’s.
Alaska Cooperative Extension
For Alaska-specific cultivar recommendations, planting calendars, and pest pressure for white spruce, the canonical source is UAF Cooperative Extension Service. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is White Spruce native to Alaska?
Yes — the USDA PLANTS Database (accessed 2026-07-01) documents White Spruce as native to Alaska. 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 White Spruce in Alaska
When can I plant White Spruce in Alaska?
Alaska's last spring hard freeze (28°F) clears between Apr 16 and May 15, and the first fall hard freeze lands between Sep 24 and Oct 29 (NOAA Regional Climate Centers ACIS, 1991-2020). No sourced winter-hardiness floor is on record for White Spruce, so this page does not state whether it overwinters in Alaska 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 White Spruce grown in across Alaska?
Alaska spans USDA hardiness zones 1a-9a (USDA ARS PHZM 2023). White Spruce carries a range of zones 2-6, so the overlap zones are where outdoor growing is most reliable.
How many frost-free days does a typical Alaska site have?
A typical Alaska site sees ~147 frost-free days per year (derived from NOAA Regional Climate Centers ACIS station record, 1991-2020). White Spruce should be matched against that window, so check whether your local microclimate runs above or below the state average before settling on a planting date.
Is White Spruce native to Alaska?
Yes — the USDA PLANTS Database (accessed 2026-07-01) documents White Spruce as native to Alaska. Planting it supports the pollinators and wildlife that evolved alongside it.
How should I amend the soil for White Spruce in Alaska?
White Spruce prefers pH 3.7-5.5 and well (dry spells) drainage (FAO ECOCROP). Most Alaska soils run mildly acidic to neutral; many sites land near this band naturally, and a soil test plus targeted sulfur or organic amendment closes any gap.
Will White Spruce actually grow on my specific land in Alaska?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores white spruce 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 Alaska
State-level data is a sketch. Your Growable Ground report scores white spruce against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Alaska white spruce averages can't show:
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