Generally — Most Areas
cardinal flower (zones 3-9) suits most of Alaska (1a-9a) — zones 3-9 are in range, and the rest of the state is the exception.
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 cardinal flower against your parcel's actual hardiness, soil, and sun.
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Zone Comparison
Cardinal Flower Needs
- USDA Zones: 3-9
- Mature size: 3 ft tall
- Picking window: ~30 days of harvest
- Drought tolerance: Low
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 3-9)
Plant data: USDA PLANTS Database / Growable Ground plant catalog. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.
When to Plant Cardinal Flower 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 cardinal flower, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether cardinal flower 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: USDA PLANTS Database. Your site's own frost dates can run earlier or later than the state range — a parcel report pins them down.
Cardinal Flower in Alaska — Quick Answer
- Verdict: Generally — Most Areas
- Plant Zones: 3-9 (USDA PLANTS Database)
- State Zones: 1a-9a (USDA ARS PHZM 2023)
- Growing Season: 28°F hard freezes about Apr 16 - May 15 to Sep 24 - Oct 29 (NOAA Regional Climate Centers ACIS, 1991-2020)
What Else to Consider for Cardinal Flower 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 cardinal flower — is covered on the Alaska growing guide.
Where in Alaska Cardinal Flower Is Zone-Hardy
Cardinal Flower is rated for USDA zones 3–9. 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 cardinal flower 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". Cardinal Flower’s zone 3–9 band: USDA PLANTS / Growable Ground plant database. A parcel report resolves your address’s own zone and frost dates rather than its county’s.
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 cardinal flower (USDA PHZM 2023):
Pollinator + Wildlife Value
Cardinal Flower draws hummingbirds, native bees, and butterflies (high value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, cardinal flower can only work that bloom inside Alaska's frost window — roughly 147 days, opening after the last 28°F freeze (Apr 16 - May 15) and closing at the first (Sep 24 - Oct 29), per NOAA Regional Climate Centers ACIS station record, 1991-2020.
Alaska Cooperative Extension
For Alaska-specific cultivar recommendations, planting calendars, and pest pressure for cardinal flower, the canonical source is UAF Cooperative Extension Service. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Cardinal Flower native to Alaska?
Cardinal Flower is native to parts of the Lower 48, but the USDA PLANTS Database (accessed 2026-07-01) does not document a native range in Alaska. It can still earn a place in a Alaska garden — the zone comparison above tells you whether it will thrive.
Looking for plants that belong here? The Alaska growing guide lists USDA-documented natives for the state.
Native-range data: USDA PLANTS Database state-distribution records, accessed 2026-07-01.
Common Questions About Growing Cardinal Flower in Alaska
When can I plant Cardinal Flower 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 Cardinal Flower, 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 Cardinal Flower grown in across Alaska?
Alaska spans USDA hardiness zones 1a-9a (USDA ARS PHZM 2023). Cardinal Flower carries a range of zones 3-9, 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). Cardinal Flower 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 Cardinal Flower native to Alaska?
Cardinal Flower is native to parts of the Lower 48, but the USDA PLANTS Database (accessed 2026-07-01) does not document a native range in Alaska. It can still earn a place in a Alaska garden — the zone comparison above tells you whether it will thrive.
Will Cardinal Flower actually grow on my specific land in Alaska?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores cardinal flower 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 cardinal flower against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Alaska cardinal flower averages can't show:
We read public map data around Alaska — soil, climate, flood, and parcel records. How we handle your address.
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Growing guides for cardinal flower
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