Unlikely — Zone Mismatch
autumn fern (zones 6-8) does not overlap with Minnesota's zone range (3a-5a). Growing outdoors is unlikely without significant protection.
One zone short — what would close it
Autumn Fern is hardy to zone 6, and the warmest ground in Minnesota is zone 5 — 1 zone short. Planted in open ground it will not survive a Minnesota winter. To grow it here, grow autumn fern in a hoop house or unheated greenhouse — its modeled 1.5-zone lift covers this gap.
A hoop house or unheated greenhouse is the lift this needs. How a greenhouse changes what you can grow →
Zone math from 6-8 (plant) against 3-5 (Minnesota). Lift modeled by crop_engine.GREENHOUSE_ZONE_MODIFIER_BY_SUBTYPE['hoop_house'] (+1.5 zones) via api/fast_sections.py Unlock Engine v2.
Autumn Fern in Minnesota — the short answer
Autumn Fern in Minnesota: hardy in zones 6–8, part sun, against a state median of ~174 frost-free days.
- Plant zones
- 6-8
- 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
- Minnesota zones
- 3a-5a
- USDA PHZM 2023
- Frost window
- Apr 19 - Apr 30 – Oct 10 - Oct 17
- NOAA RCC ACIS 1991-2020, 28°F
- Shortest county season
- 137 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.
Minnesota spans zones 3a-5a, but your yard has its own microclimate — slope, trees, and low spots shift frost and sun across a single parcel. Enter your address and we'll score autumn fern 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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Minnesota is not one climate
A single Minnesota answer averages 87 counties whose growing seasons are 62 days apart — from 137 frost-free days in Lake County to 199 in Ramsey County. Which end of that your land sits nearer changes what autumn fern can finish before the first hard freeze.
The middle half of 87 counties runs 162–181 days, with a median of 174 days — a 62-day span end to end.
Measured across 87 Minnesota counties. NOAA Regional Climate Centers ACIS, 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 Autumn Fern Stands in Minnesota
Autumn Fern is rated for zones 6–8 — a cold floor USDA puts at -10 to 0°F. No Minnesota 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 Minnesota winters, not about autumn fern.
Below the zone 6 floor
87 counties
- Beltrami County · zone 3b
- Clearwater County · zone 3b
- Hubbard County · zone 3b
3 of 87 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
Autumn Fern Needs
- USDA Zones: 6-8
- Sun: Part Sun
- Mature size: 2 ft tall
- Drought tolerance: Low
Minnesota Has
- USDA Zones: 3a-5a
- Last Hard Freeze (28°F): Apr 19 - Apr 30
- First Hard Freeze (28°F): Oct 10 - Oct 17
- Annual Rainfall: 19-34 inches
- Common Soils: Prairie loam, Clay, Sandy outwash
Plant Zone Range (zones 6-8)
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 Autumn Fern in Minnesota
The frost window
Across Minnesota, the last spring hard freeze (28°F) clears between Apr 19 and Apr 30, and the first fall hard freeze lands between Oct 10 and Oct 17 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 163-day window you can count on — up to 181 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.
Timing tuned to sub-state frost dates — Lake 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.
Soil + Drainage Fit
Drainage requirement: poorly (saturated >50% of year). A soil-survey lookup (NRCS SSURGO) flags whether your specific site matches.
Your land, not the state average
Minnesota's soils run mostly loam, but SSURGO maps the series, texture, and drainage under your exact parcel. What matters for autumn fern is the horizon its roots actually work, not the surface. That map unit, not the state average, decides how autumn 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. Minnesota soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
What Else to Consider for Autumn Fern in Minnesota
Zone compatibility tells you about winter cold survival — but Minnesota growers also need to think about:
Extreme cold (zone 3a: -40F) limits many species
Short growing season (100-140 frost-free days)
Heavy clay soils in the Red River Valley
What to actually do about these — and the constraints that apply to every Minnesota grower, not just autumn fern — is covered on the Minnesota growing guide.
Timing shifts within Minnesota
Minnesota isn't one climate. In Lake County, the last hard freeze (28°F) holds until about May 14 — roughly 23 days later than the recorded state median — so plant autumn fern to your county's window, not the statewide date.
County last-freeze dates: NOAA Regional Climate Centers ACIS (1991-2020), county 28°F freeze (earlier than the folk 32°F "last frost"). A parcel report resolves your address's own frost dates.
Where in Minnesota Autumn Fern Is Zone-Hardy
Autumn Fern is rated for USDA zones 6–8. No Minnesota county reaches it. Even Watonwan County, the state’s mildest winter at zone 5a, sits below the plant’s zone 6 floor — so in open ground this one needs winter protection here, or a container that comes under cover.
Across those 87 counties Minnesota’s winter-low ladder runs from zone 3b in Beltrami County to zone 5a in Watonwan County — 1.5 USDA zones of spread, which is 15°F between the two counties’ average coldest night of the year. None of that range reaches the band autumn fern needs, so here the statewide answer really is the answer.
County hardiness zones: USDA Plant Hardiness Zone Map (PHZM) 2023, per county. Autumn Fern’s zone 6–8 band: USDA PLANTS / Growable Ground plant database. A parcel report resolves your address’s own zone and frost dates rather than its county’s.
Recommended Autumn Fern Varieties for Minnesota
Minnesota publishes no state variety trial for autumn fern, so we won't invent a "best for Minnesota" list. Choose types rated to your USDA hardiness zone (3a-5a), and confirm winter survival and drainage against your own parcel.
Minnesota Cooperative Extension
For Minnesota-specific cultivar recommendations, planting calendars, and pest pressure for autumn fern, the canonical source is University of Minnesota Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Common Questions About Growing Autumn Fern in Minnesota
When can I plant Autumn Fern in Minnesota?
Minnesota's last spring hard freeze (28°F) clears between Apr 19 and Apr 30, and the first fall hard freeze lands between Oct 10 and Oct 17 (NOAA Regional Climate Centers ACIS, 1991-2020). Time outdoor planting to after the last hard freeze for your specific site — a further two to three weeks for anything tender — and count back from those dates for transplant scheduling.
What hardiness zone is Autumn Fern grown in across Minnesota?
Minnesota spans USDA hardiness zones 3a-5a (USDA ARS PHZM 2023). Autumn Fern carries a range of zones 6-8, so the overlap zones are where outdoor growing is most reliable.
How many frost-free days does a typical Minnesota site have?
A typical Minnesota site sees ~174 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Autumn Fern 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. In cooler counties like Lake, the freeze-free season runs shorter than the state average, so verify your own county's window.
Will Autumn Fern actually grow on my specific land in Minnesota?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores autumn 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 Minnesota
State-level data is a sketch. Your Growable Ground report scores autumn fern against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Minnesota autumn fern averages can't show:
We read public map data around Minnesota — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Minnesota autumn fern average
Explore More
Growing guides for autumn fern
Explore Minnesota county by county
Minnesota carries 87 counties with their own USDA zone — a sample of the growing pages for autumn fern there:
Where else autumn fern grows
Autumn Fern's zone band crosses state lines — these are the states closest to Minnesota in winter climate where it also has a page, plus the far ends of its range. Each one re-answers the question with that state's own record.
More to grow in Minnesota
Minnesota has a growing page for 747 plants — a rotating sample of the rest of the shelf.
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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