black-eyed Susan (Rudbeckia hirta), photographi

Can I Grow Black Eyed Susan in Maine?

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

Yes — Strong Match

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

Black Eyed Susan in Maine — the short answer

Black Eyed Susan in Maine: hardy in zones 3–7, full sun, against a state median of ~182 frost-free days.

Plant zones
3-7
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
120 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.

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Your yard isn't the whole zone.

Maine spans zones 3b-7a, 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 black eyed susan against your land's actual soil, sun, and frost.

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Maine is not one climate

A single Maine answer averages 16 counties whose growing seasons are 79 days apart — from 143 frost-free days in Franklin County to 222 in Knox County. Which end of that your land sits nearer changes what black eyed susan can finish before the first hard freeze.

143 daysFranklin County222 daysKnox County

The middle half of 16 counties runs 154191 days, with a median of 178 days — a 79-day span end to end.

Measured across 16 Maine 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 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 black eyed susan (USDA PHZM 2023):

Zone Comparison

Black Eyed Susan Needs

  • USDA Zones: 3-7
  • Sun: Full Sun
  • Mature size: 1 ft tall
  • Picking window: ~45 days of harvest
  • 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 3-7)

3a
7b
3a (Cold)13b (Hot)

Preferred Soil pH

3.5 (Acidic)7.0 (Neutral)9.0 (Alkaline)
Highlighted range: pH 5.58.0

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 Black Eyed Susan 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.

Frost tenderness

Black Eyed Susan is frost-tender — FAO ECOCROP puts its killing temperature at 32°F — so set plants out two to three weeks PAST your local last hard freeze, not on it and not on the state's earliest date. The 28°F marker above is when killing freezes stop, not when light frost does. That is the point where cold damages growing tissue, not a winter-survival floor — an established perennial comes through far colder while dormant, which is what its hardiness zone tells you.

When to start the seed

Those dates are when black eyed susan goes out, not when it starts. It is sown under cover about 8 weeks ahead, so counting back from Maine's late-side last freeze of May 3 is what fixes your sowing date — and a yard that clears frost earlier than the state's late date starts earlier still.

Days to maturity vs. the window

At 120 days to maturity (Growable Ground Plant Database), counting from the last hard freeze it ripens with 40 days to spare even in Maine's tightest freeze scenario — room for a later start or a second sowing.

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 black eyed susan survives winter here. Whether the season is long enough — and warm enough — is a different question.

Days to maturity

Black Eyed Susan matures in ~120 days (Growable Ground Plant Database). A typical Maine site has ~182 frost-free days, so plenty of room for a second succession.

Growing degree days

Black Eyed Susan needs ~1000 GDD (base 50°F) to ripen. The state median runs ~1450 GDD (from PRISM 1991-2020 climate normals), so Maine's typical season clears that easily.

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

Black Eyed Susan likes near-neutral soil (pH 5.5-8). 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 7.5 — 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.

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 Black Eyed Susan 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 black eyed susan — is covered on the Maine growing guide.

Timing shifts within Maine

Black Eyed Susan needs about 120 days of frost-free season from planting to harvest. Even Franklin County — Maine’s shortest season at 143 frost-free days — clears that by 23 days, so season length isn’t the constraint anywhere in Maine. What varies is your own parcel.

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 black eyed susan about 62 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"). Black Eyed Susan's 120-day requirement: USDA PLANTS / Growable Ground plant database (days to maturity). A parcel report resolves your address's own frost dates.

Pollinator + Wildlife Value

Black Eyed Susan draws honeybees, native bees, and butterflies (high value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, black eyed susan 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 black eyed susan, the canonical source is UMaine Cooperative Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.

Is Black Eyed Susan native to Maine?

Yes — the USDA PLANTS Database (accessed 2026-07-01) documents Black Eyed Susan 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 Black Eyed Susan in Maine

When can I plant Black Eyed Susan 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). Black Eyed Susan is frost-tender — its killing temperature is 32°F (FAO ECOCROP — the point where cold damages growing tissue, not a winter-survival floor) — so wait two to three weeks past your site's last hard freeze, when light frost has also stopped, before planting out.

Can Black Eyed Susan mature before first frost in Maine?

Yes — Black Eyed Susan matures in 120 days (Growable Ground Plant Database), and Maine's dependable hard-freeze-free window runs 160 days (NOAA Regional Climate Centers ACIS, 1991-2020), leaving 40 days of margin. Plant once the last hard freeze has passed — two to three weeks later for anything tender — and it ripens ahead of the first fall freeze.

What hardiness zone is Black Eyed Susan grown in across Maine?

Maine spans USDA hardiness zones 3b-7a (USDA ARS PHZM 2023). Black Eyed Susan carries a range of zones 3-7, 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). Black Eyed Susan 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 Black Eyed Susan native to Maine?

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

How should I amend the soil for Black Eyed Susan in Maine?

Black Eyed Susan prefers pH 5.5-8 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 Black Eyed Susan actually grow on my specific land in Maine?

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

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Check your specific parcel in Maine

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

Three things about your lot that Maine black eyed susan 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 black eyed susan average

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