hardy kiwi (Actinidia arguta), photographi

Can I Grow Hardy Kiwi in Maine?

USDA Zones 3b-7a · Plant zone range 3-8

Yes — Strong Match

hardy kiwi (zones 3-8) covers every zone Maine contains (3b-7a), so hardiness is not what limits it anywhere in the state.

Hardy Kiwi in Maine — the short answer

Hardy Kiwi in Maine: hardy in zones 3–8, part sun, against a state median of ~182 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
Maine zones
3b-7a
USDA PHZM 2023
Frost window
Apr 16 - May 3 – Oct 10 - Oct 24
NOAA RCC ACIS 1991-2020, 28°F
Shortest county season
143 days
NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze
Days to maturity
1460 days
Growable Ground Plant Database

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.

Score your parcel · free

Your yard isn't the whole zone.

Maine spans zones 3b-7a, 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 hardy kiwi 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.

No card required · your full report in seconds

Maine is not one climate

Maine’s winter-low ladder runs across 16 counties, from zone 4 in Aroostook County to zone 6 in Lincoln County. That is 20°F between the two counties’ average coldest night — the difference between hardy kiwi overwintering in the ground and coming under cover.

4 zonesAroostook County6 zonesLincoln County

The middle half of 16 counties runs 4.55.5 zones, with a median of 5.5 zones — a 2-zone span end to end.

Measured across 16 Maine 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 Maine Fits Best

Even within Maine's zones 3b-7a, county microclimates differ enough to change what thrives. These counties carry the closest zone match for hardy kiwi (USDA PHZM 2023):

Zone Comparison

Hardy Kiwi Needs

  • USDA Zones: 3-8
  • Frost-Free Days: 150+
  • Sun: Part Sun
  • Mature size: 25 ft tall
  • Picking window: ~30 days of harvest
  • Drought tolerance: Low

Maine Has

  • USDA Zones: 3b-7a
  • Last Hard Freeze (28°F): Apr 16 - May 3
  • First Hard Freeze (28°F): Oct 10 - Oct 24
  • Annual Rainfall: 36-50 inches
  • Common Soils: Glacial till, Sandy loam, Rocky loam

Plant Zone Range (zones 3-8)

3a
8b
3a (Cold)13b (Hot)

Preferred Soil pH

3.5 (Acidic)7.0 (Neutral)9.0 (Alkaline)
Highlighted range: pH 4.57.0

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 Hardy Kiwi in Maine

The frost window

Across Maine, the last spring hard freeze (28°F) clears between Apr 16 and May 3, and the first fall hard freeze lands between Oct 10 and Oct 24 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 160-day window you can count on — up to 191 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

Maine runs as cold as USDA zone 3, and no sourced winter-hardiness floor is on record for hardy kiwi, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether hardy kiwi is a permanent planting or a replant-every-spring crop for you turns on your own zone within Maine; check its hardiness range against that before treating it as long-lived ground.

Timing tuned to sub-state frost dates — Piscataquis 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 hardy kiwi survives winter here. Whether the season is long enough — and warm enough — is a different question.

Frost-free days

Hardy Kiwi wants 150+ frost-free days; a typical Maine site sees ~182 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves a workable window — start indoors to bank time.

Growing degree days

Hardy Kiwi needs ~2200 GDD (base 50°F) to ripen. The state median runs ~1450 GDD (from PRISM 1991-2020 climate normals), so Maine's typical season runs short on heat — pick a south-facing site and consider season extension.

Chill hours

Hardy Kiwi requires ~600 chill hours (32-45°F dormancy window). Maine typically banks ~2500 chill hours per winter (from PRISM 1991-2020 climate normals), which keeps this plant on track.

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

Hardy Kiwi likes near-neutral soil (pH 4.5-7). That's the common-ground band across Maine's glacial till and sandy loam — a soil test confirms it for your site. It will grow across that whole span, but it does best between pH 5 and 6.5 — worth knowing before you decide whether a Maine soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Maine site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.

Your land, not the state average

SSURGO maps about 27.4% of Maine as poorly or somewhat-poorly drained, and the class flips parcel to parcel. Hardy Kiwi has low drought tolerance, so it is the fast-draining end that will cost you — your soil map unit, not the state average, is the real answer.

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. Maine soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.

Before you plant hardy kiwi for food

Anything you grow to eat takes up what is in the ground it grows in, so what is on record near you is worth knowing before hardy kiwi goes in. What follows is Maine’s documented federal record at state scale — a screening signal, not a soil test, and not a statement about any one lot.

Safe to Grow Here?

What the federal record shows across Maine — and how to grow with it.

Federal record: High

We checked the federal record across Maine10,103 documented sites across 8 of the 9 source types we track.

The most significant on record: 99 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.

Maine carries one of the heavier federal records we track — and that's not a verdict on your yard. Proximity to a documented site is information, not a diagnosis: nothing here says any particular parcel is affected. It does earn one concrete step — before food beds go in the ground, a professional soil test tells you exactly what you're working with, and raised beds with clean imported soil grow well almost anywhere in the meantime.

Severity Distribution

across Maine

High163Moderate3,125Low6,815

Highest-Severity Sites

Acton Area Mines
Mining Sites · Past Producer
Acton Mine
Mining Sites · Past Producer
Argonaut Mine
Mining Sites · Past Producer
Belfast Water District
PFAS Sampling · PFAS Detected
Brunswick Naval Air Station
Superfund · Superfund NPL

Know Before You Grow

  • Underground tanks leak petroleum as they age — near a former filling station, test the soil.
  • Near a brownfield, raised beds of imported soil give your food clean ground.
  • On a private well, test for nitrates: above 10 mg/L the water needs treatment before irrigating.

Sources: EPA, USGS1.8M documented sites tracked nationwide across 9 federal source types.

What Else to Consider for Hardy Kiwi in Maine

Zone compatibility tells you about winter cold survival — but Maine growers also need to think about:

Very short growing season (100-140 frost-free days)

Rocky glacial soils require significant clearing

Harsh winters with heavy snow and ice

Growing hardy kiwi here specifically

Hardy Kiwi roots run medium and prefer pH 4.5–7.0, but drainage comes first here: SSURGO maps about 27.4% of Maine as poorly or somewhat-poorly drained, and wet ground rots its crown before pH ever matters.

Plant hardy kiwi on a raised, gravel-amended berm so water drains fast and the crown stays dry. How to handle it →

What to actually do about these — and the constraints that apply to every Maine grower, not just hardy kiwi — is covered on the Maine growing guide.

Timing shifts within Maine

Maine isn't one climate. In Piscataquis County, the last hard freeze (28°F) holds until about May 15 — roughly 23 days later than the recorded state median — so plant hardy kiwi to your county's window, not the statewide date.

Hardy Kiwi needs about 150 days of frost-free season to complete its cycle. 14 of Maine’s 16 counties give it that outright. The tightest that does is Aroostook County at 153 frost-free days — 3 to spare. Below that line you are transplanting or extending the season, not direct-sowing.

Across Maine’s 16 counties the frost-free season runs from 143 days in Franklin County to 222 days in Knox County — a spread of 79 days, which is why a single statewide planting date misleads. The median Maine county sees 182 frost-free days, leaving hardy kiwi about 32 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"). Hardy Kiwi's 150-day requirement: USDA PLANTS / Growable Ground plant database (minimum frost-free days). A parcel report resolves your address's own frost dates.

Pollinator + Wildlife Value

Hardy Kiwi draws honeybees and native bees (moderate value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, hardy kiwi can only work that bloom inside Maine's frost window — roughly 182 days, opening after the last 28°F freeze (Apr 16 - May 3) and closing at the first (Oct 10 - Oct 24), per NOAA Regional Climate Centers ACIS, 1991-2020.

Maine Cooperative Extension

For Maine-specific cultivar recommendations, planting calendars, and pest pressure for hardy kiwi, the canonical source is UMaine Cooperative Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.

Is Hardy Kiwi native to Maine?

No — the USDA PLANTS Database lists Hardy Kiwi as introduced rather than native in the Lower 48, so it is not part of Maine's native flora. It grows here as a garden plant; pairing it with a few Maine natives keeps local pollinators fed too.

Looking for plants that belong here? The Maine 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 Hardy Kiwi in Maine

When can I plant Hardy Kiwi in Maine?

Maine's last spring hard freeze (28°F) clears between Apr 16 and May 3, and the first fall hard freeze lands between Oct 10 and Oct 24 (NOAA Regional Climate Centers ACIS, 1991-2020). No sourced winter-hardiness floor is on record for Hardy Kiwi, so this page does not state whether it overwinters in Maine 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 Hardy Kiwi grown in across Maine?

Maine spans USDA hardiness zones 3b-7a (USDA ARS PHZM 2023). Hardy Kiwi 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 Maine site have?

A typical Maine site sees ~182 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Hardy Kiwi needs 150+ 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 Piscataquis, the freeze-free season runs shorter than the state average, so verify your own county's window.

Is Hardy Kiwi native to Maine?

No — the USDA PLANTS Database lists Hardy Kiwi as introduced rather than native in the Lower 48, so it is not part of Maine's native flora. It grows here as a garden plant; pairing it with a few Maine natives keeps local pollinators fed too.

How should I amend the soil for Hardy Kiwi in Maine?

Hardy Kiwi prefers pH 4.5-7 and well (dry spells) drainage (FAO ECOCROP). That sits in the common-ground band across Maine soils — a 30-minute soil test from a local Extension lab confirms it for your specific site.

Will Hardy Kiwi actually grow on my specific land in Maine?

State-level zone + climate data is a sketch. A Growable Ground parcel report scores hardy kiwi against your address's exact soil pH, drainage, sun, and frost-date data drawn from USDA SSURGO, NOAA, and PRISM — not state averages.

Free Report

Check your specific parcel in Maine

State-level data is a sketch. Your Growable Ground report scores hardy kiwi against your parcel's exact soil, sun, drainage, and frost data — not zone averages.

Three things about your lot that Maine hardy kiwi averages can't show:

Your soil pHYour frost-free days — Maine averages 182Your sun & shade

We read public map data around Maine — soil, climate, flood, and parcel records. How we handle your address.

25+ data sources read at your address, not the Maine hardy kiwi 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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