green ash (Fraxinus pennsylvanica), photographi

Can I Grow Green Ash in Maine?

USDA Zones 3b-7a · Plant zone range 2-9

Yes — Strong Match

green ash (zones 2-9) covers every zone Maine contains (3b-7a), so hardiness is not what limits it anywhere in the state.

Green Ash in Maine — the short answer

Green Ash in Maine: hardy in zones 2–9, full sun, against a state median of ~182 frost-free days.

Plant zones
2-9
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

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 green ash 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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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 green ash 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 green ash (USDA PHZM 2023):

Zone Comparison

Green Ash Needs

  • USDA Zones: 2-9
  • Sun: Full Sun
  • Mature size: 60 ft tall
  • Drought tolerance: Medium

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 2-9)

2a
9b
3a (Cold)13b (Hot)

Preferred Soil pH

3.5 (Acidic)7.0 (Neutral)9.0 (Alkaline)
Highlighted range: pH 6.08.5

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 Green Ash 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 green ash, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether green ash 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.

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 green ash survives winter here. Whether the season is long enough — and warm enough — is a different question.

Chill hours

Green Ash requires ~500 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

Green Ash likes near-neutral soil (pH 6-8.5). 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 6.5 and 8 — 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.

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.

What Else to Consider for Green Ash 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

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

Where in Maine Green Ash Is Zone-Hardy

Green Ash is rated for USDA zones 29. Every one of Maine’s 16 counties sits inside that band — from Aroostook County at zone 4a to Lincoln County at zone 6a — 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 16 counties Maine’s winter-low ladder runs from zone 4a in Aroostook County to zone 6a in Lincoln County 2 USDA zones of spread, which is 20°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. Piscataquis County holds its last hard freeze (28°F) until about May 15, while Knox County is clear by Apr 4 41 days apart. Set green ash 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". Green Ash’s zone 29 band: USDA PLANTS / Growable Ground plant database. A parcel report resolves your address’s own zone and frost dates rather than its county’s.

Maine Cooperative Extension

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

Is Green Ash native to Maine?

Yes — the USDA PLANTS Database (accessed 2026-07-01) documents Green Ash as native to Maine. 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 Green Ash in Maine

When can I plant Green Ash 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 Green Ash, 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 Green Ash grown in across Maine?

Maine spans USDA hardiness zones 3b-7a (USDA ARS PHZM 2023). Green Ash carries a range of zones 2-9, 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). Green Ash 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 Green Ash native to Maine?

Yes — the USDA PLANTS Database (accessed 2026-07-01) documents Green Ash as native to Maine. Planting it supports the pollinators and wildlife that evolved alongside it.

How should I amend the soil for Green Ash in Maine?

Green Ash prefers pH 6-8.5 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 Green Ash actually grow on my specific land in Maine?

State-level zone + climate data is a sketch. A Growable Ground parcel report scores green ash 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 green ash against your parcel's exact soil, sun, drainage, and frost data — not zone averages.

Three things about your lot that Maine green ash 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 green ash average

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