Generally — Most Areas
lady fern (zones 4-10) suits most of Alaska (1a-9a) — zones 4-9 are in range, and the rest of the state is the exception.
Lady Fern in Alaska — the short answer
Lady Fern in Alaska: hardy in zones 4–10, shade, against a state median of ~147 frost-free days.
- Plant zones
- 4-10
- 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 lady fern against your parcel's actual hardiness, soil, and sun.
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
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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 lady fern 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 Lady Fern Stands in Alaska
Lady Fern is rated for zones 4–10 — a cold floor USDA puts at -30 to -20°F. No Alaska county sits inside it, so in open ground this is a grown-under-cover plant here rather than a bed plant — which is a statement about Alaska winters, not about lady fern.
Below the zone 4 floor
30 counties
- Aleutians East County · zone 3a-4b
- Aleutians West County · zone 3a-4b
- Anchorage County · zone 3a-4b
3 of 30 shown
Winter cold is the limit here — the same plant works in a container that comes under cover.
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.
Zone Comparison
Lady Fern Needs
- USDA Zones: 4-10
- Frost-Free Days: 80+
- Sun: Shade
- Mature size: 3 ft tall
- 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 4-10)
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 Lady Fern 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 lady fern, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether lady fern 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.
Timing tuned to sub-state frost dates — North Slope County, not the statewide average.
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 lady fern survives winter in part of Alaska, not across all of it. Whether the season is long enough — and warm enough — is a different question.
Frost-free days
Lady Fern wants 80+ frost-free days; a typical Alaska site sees ~147 (NOAA Regional Climate Centers ACIS station record, 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 station record, 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
Lady Fern likes near-neutral soil (pH 4.5-7). That's the common-ground band across Alaska's permafrost and glacial silt — a soil test confirms it for your site.
Your land, not the state average
Alaska's soils run mostly silt loam, but SSURGO maps the series, texture, and drainage under your exact parcel. What matters for lady fern is the horizon its roots actually work, not the surface. That map unit, not the state average, decides how lady fern performs.
Check your parcel → Source: USDA NRCS SSURGO.
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 Lady Fern 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
Growing lady fern here specifically
Alaska's soils run mostly silt loam (Spodosols), and whether that suits lady fern's pH 4.5–7.0 preference comes down to your exact parcel, not the statewide picture.
Pull your parcel's SSURGO map unit, test pH, and amend toward lady fern's 4.5–7.0 target before planting. How to handle it →
What to actually do about these — and the constraints that apply to every Alaska grower, not just lady fern — is covered on the Alaska growing guide.
Timing shifts within Alaska
Alaska isn't one climate. In North Slope County, the last hard freeze (28°F) holds until about Jun 7 — roughly 33 days later than the recorded state median — so plant lady fern to your county's window, not the statewide date.
Lady Fern needs about 80 days of frost-free season to complete its cycle. Even Southeast Fairbanks County — Alaska’s shortest season at 85 frost-free days — clears that by 5 days, so season length isn’t the constraint anywhere in Alaska. What varies is your own parcel.
Across Alaska’s 28 counties the frost-free season runs from 85 days in Southeast Fairbanks County to 240 days in Sitka County — a spread of 155 days, which is why a single statewide planting date misleads. The median Alaska county sees 147 frost-free days, leaving lady fern about 67 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"). Lady Fern's 80-day requirement: USDA PLANTS / Growable Ground plant database (minimum frost-free days). A parcel report resolves your address's own frost dates.
Recommended Lady Fern Varieties for Alaska
Alaska publishes no state variety trial for lady fern, so we won't invent a "best for Alaska" list. Choose types rated to your USDA hardiness zone (1a-9a), and confirm winter survival and drainage against your own parcel.
Alaska Cooperative Extension
For Alaska-specific cultivar recommendations, planting calendars, and pest pressure for lady fern, the canonical source is UAF Cooperative Extension Service. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Lady Fern native to Alaska?
Yes — the USDA PLANTS Database (accessed 2026-07-01) documents Lady Fern 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 Lady Fern in Alaska
When can I plant Lady Fern 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 Lady Fern, 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 Lady Fern grown in across Alaska?
Alaska spans USDA hardiness zones 1a-9a (USDA ARS PHZM 2023). Lady Fern carries a range of zones 4-10, 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). Lady Fern needs 80+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date. In cooler counties like North Slope, the freeze-free season runs shorter than the state average, so verify your own county's window.
Is Lady Fern native to Alaska?
Yes — the USDA PLANTS Database (accessed 2026-07-01) documents Lady Fern as native to Alaska. Planting it supports the pollinators and wildlife that evolved alongside it.
How should I amend the soil for Lady Fern in Alaska?
Lady Fern prefers pH 4.5-7 (USDA PLANTS). That sits in the common-ground band across Alaska soils — a 30-minute soil test from a local Extension lab confirms it for your specific site.
Will Lady Fern actually grow on my specific land in Alaska?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores lady fern 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 lady fern against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Alaska lady fern averages can't show:
We read public map data around Alaska — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Alaska lady fern average
Analysis by the Growable Ground research team, grounded in USDA PLANTS, USDA NRCS SSURGO, NOAA Climate Normals (1991-2020), and named Cooperative Extension sources. How we know →
Cite this dataset
Kirchick, M. (2026). Growable Ground Plant Database [Data set]. Zenodo. https://doi.org/10.5281/zenodo.21435643
Licensed CC BY-NC 4.0. DOI 10.5281/zenodo.21435643
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