What Grows in Dexter, Maine

USDA Zones 5a · 3K acres

Dexter, Maine, sits in USDA hardiness zone 5a — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.

Well-matched crops include cabbage, cranberry, lavender, and collard greens, and the gap between "grows in the area" and "grows in your yard" is closed by soil, sun, and drainage.

Score your parcel · free

Even in Dexter, no two yards are alike.

A low spot, a south-facing slope, or a stand of trees moves the frost date and sun across a single Dexter lot. Enter your address and we'll score 1,086 plants against your land's actual soil, sun, and frost.

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

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Dexter — the short answer

Dexter, Maine: USDA zone 5a, about 171 days between hard freezes, across 3K acres of town.

USDA zone
5a
USDA PHZM 2023
Last hard freeze (28°F)
Apr 25
NOAA 1991–2020 Climate Normals, 28°F — this town
First hard freeze (28°F)
Oct 13
NOAA 1991–2020 Climate Normals, 28°F — this town
Days between freezes
~171
NOAA 1991–2020 Climate Normals, 28°F — this town
Town area
3K acres
US Census TIGER/Line 2025

Every figure names the dataset it came from. Hard-freeze dates are this town’s own 28°F normals: light frosts run a few weeks past them, and tender transplants usually wait 2–3 weeks after the last hard freeze.

Hardiness Zone Range

5a5a
3a (Cold)13b (Hot)

Zone 5a is Dexter's average, not your lot's — a low corner or a tree line moves it. Against Dexter's 171-day season, see what your own ground reads.

Soil varies lot by lot — soil types explained.

What this means for growing in Dexter

Each reading below is measured for Dexter itself — here is what it means for a garden here, and the move an experienced grower makes about it.

Season length

Measured

Dexter runs about 171 days between hard freezes — a moderate growing season.

There is room for the full run of cool-season crops plus a warm-season main crop, but the calendar is tight enough that a late spring or early fall frost still decides how much finishes.

Time warm-season transplants to your last hard freeze, and a few weeks of season extension turns a near-miss harvest into a sure one.

NOAA 1991–2020 Climate Normals

Winter hardiness

Measured

Dexter sits in USDA hardiness zone 5a.

The zone sets which perennials, shrubs, and fruit trees live through an average winter here — a plant rated for a colder zone is a safe bet, one rated warmer needs winter protection or gets treated as an annual.

Match perennials and fruit to the zone before you buy, so nothing you plant is a gamble against the cold.

USDA PHZM 2023

The kind of country Dexter is in

Dexter sits in the Acadian Plains and Hills — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Dexter's own centroid rather than borrowed from Penobscot County.

What that means for soil

What Grows in Dexter

Every plant below cleared Dexter's own zone 5a and its 171-day season. Each card opens that plant's Maine profile. How we score.

cabbage, photograph
Growing cabbage in MaineZones 2–11Dexter's 5a — 3 zones of cold margin.
cranberry, photograph
Maine cranberry guideZones 2–7Dexter's 5a — 3 zones of cold margin.
lavender, photograph
Lavender in MaineZones 5–8Dexter's 5a is its exact cold limit.
collard greens, photograph
Collard greens: Maine growing notesZones 2–11Dexter's 5a — 3 zones of cold margin.
hazelnut, photograph
Growing hazelnut in MaineZones 4–9Dexter's 5a — 1 zone of cold margin.
French tarragon, photograph
Maine french tarragon guideZones 3–7Dexter's 5a — 2 zones of cold margin.
garlic, photograph
Garlic in MaineZones 2–10Dexter's 5a — 3 zones of cold margin.
blueberry, photograph
Blueberry: Maine growing notesZones 3–8Dexter's 5a — 2 zones of cold margin.
St. Johns wort, photograph
Growing st. johns wort in MaineZones 3–8Dexter's 5a — 2 zones of cold margin.
kale, photograph
Maine kale guideZones 2–11Dexter's 5a — 3 zones of cold margin.
blackberry, photograph
Blackberry in MaineZones 5–8Dexter's 5a is its exact cold limit.
lentil, photograph
Lentil: Maine growing notesZones 2–11Dexter's 171 days clear the ~70 it needs.
okra, photograph
Growing okra in MaineZones 2–12Dexter's 171 days clear the ~50 it needs.
potato, photograph
Maine potato guideZones 2–11Dexter's 5a — 3 zones of cold margin.
pumpkin, photograph
Pumpkin in MaineZones 3–11Dexter's 171 days clear the ~40 it needs.
hosta, photograph
Hosta: Maine growing notesZones 3–8Dexter's 5a — 2 zones of cold margin.
sunflower, photograph
Growing sunflower in MaineZones 2–11Dexter's 171 days clear the ~70 it needs.
azalea, photograph
Maine azalea guideZones 4–8Dexter's 5a — 1 zone of cold margin.
hops, photograph
Hops in MaineZones 3–8Dexter's 5a — 2 zones of cold margin.
iris, photograph
Iris: Maine growing notesZones 3–10Dexter's 5a — 2 zones of cold margin.
French marigold, photograph
Growing french marigold in MaineDexter's 171 days clear the ~50 it needs.
lilac, photograph
Maine lilac guideZones 4–10Dexter's 5a — 1 zone of cold margin.
American bittersweet, photograph
American bittersweet in MaineZones 3–8Dexter's 5a — 2 zones of cold margin.
Canada anemone, photograph
Canada anemone: Maine growing notesZones 3–8Dexter's 5a — 2 zones of cold margin.
American elm, photograph
Growing american elm in MaineZones 3–9Dexter's 5a — 2 zones of cold margin.
alfalfa, photograph
Maine alfalfa guideZones 2–10Dexter's 171 days clear the ~100 it needs.
Kentucky bluegrass, botanical illustration
Kentucky bluegrass in MaineZones 2–7Dexter's 5a — 3 zones of cold margin.
blue spruce, photograph
Blue spruce: Maine growing notesZones 2–8Dexter's 5a — 3 zones of cold margin.
annual ryegrass, photograph
Growing annual ryegrass in MaineZones 3–10Dexter's 171 days clear the ~90 it needs.
Canada wild rye, photograph
Maine canada wild rye guideZones 3–8Dexter's 5a — 2 zones of cold margin.

Is it too late to plant in Dexter?

For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Mar 28; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 25 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 13 — long-season crops need about 90 days of runway, quick greens only 30. As the window narrows, the plantings just get faster — fall brassicas, then greens, then garlic to finish.

Documented around Dexter

Spotted lanternfly documented 31 miles from Dexter, first recorded 2023. What to watch for.

What's on the federal record near Dexter

Closest first, within ~10 miles of Dexter. Listing isn't leaking, and distance isn't exposure.

  1. GOULETTE, ROLANDUnderground Storage Tanks · 650 ft
  2. C M ELLMS & SONUnderground Storage Tanks · 950 ft
  3. DEXTER SHOE COMPANY PLANT #1Toxics Release Inventory · 1300 ft
  4. DEXTER SHOE PLANT #5Toxics Release Inventory · 1500 ft
  5. SPRING ST SVC CTRUnderground Storage Tanks · 1600 ft
  6. MAINE DEPARTMENT OF TRANSPORTATIONUnderground Storage Tanks · 1600 ft
  7. FAYSCOTT, LLCToxics Release Inventory · 2400 ft
  8. FAYSCOTT, LLCBrownfields · 2400 ft
  9. BUS GARAGEUnderground Storage Tanks · 0.5 mi
  10. NORTHERN LIGHT INTERNAL MEDICINE - DEXTERBrownfields · 0.5 mi
  11. BIG APPLE DEXTERUnderground Storage Tanks · 0.5 mi
  12. NORTHERN LIGHT EMS DEXTERBrownfields · 0.6 mi

6 more sites are on the record inside the same radius. See them on the map

Measured from Dexter's center, not your beds. Run your own address for what's upwind of you specifically.

Environmental Intelligence

The counts behind that headline — every source type on the record near Dexter.

Total Sites

89

within ~10 miles of Dexter

Risk Level

Elevated

Highest-severity

3 Superfund sites

Severity Distribution

within ~10 miles of Dexter

High6Moderate25Low58

Highest-Severity Sites

Corrina Mine
Mining Sites · Past Producer
Eastland Woolen Mills INC
Superfund · Superfund NPL
Garland Mine
Mining Sites · Past Producer
Garland Prospect
Mining Sites · Unknown
Jones Hill Mine
Mining Sites · Past Producer

A note from Gnorman

What an experienced grower watches for around here

In and around Dexter, two things run higher than the national average within ~10 miles of Dexter — Superfund (3 sites) and Mining (11 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.

Superfund: Superfund sites represent the most severe contamination in the federal system.

Mining: Mining sites — both historic and active — can leach heavy metals (arsenic, lead, cadmium, mercury) into soil and water for centuries after operations cease.

Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).

Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.

Free Report

Check your specific parcel in Dexter

Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,086 plant recommendations.

25+ data sources read at your address, not the Dexter average

Your land is one point inside Dexter

Everything above resolves to Dexter as a whole — one PHZM band and one 28°F frost record, read across 3K acres. Your parcel is one point inside that footprint. Slope, tree cover, a low spot that pools cold air, and what is in the soil are all resolved at the address, and none of them are visible at town scale. That is the honest boundary of this page, and the reason the next step is a reading of your own ground rather than a better local average.

Your Lot vs the Dexter Average

Dexter Average

  • USDA Zones 5a, averaged across Dexter
  • One soil character for all of Dexter
  • Frost dates read at Dexter's scale: Apr 25 to Oct 13

YOUR Parcel

  • Your exact zone, not Dexter's 5a
  • Your SSURGO soil type & pH
  • Your sun exposure, cast in 3D

See MY Growing Report

Free Report

Read your specific parcel in Dexter

Pull a site-specific report for your exact address in Dexter, Maine — soil, sun, drainage, frost risk, and scored plant recommendations.

Three things about your lot that Dexter averages can't show:

Your soil pHYour frost-free days — Dexter averages 171Your sun & shade

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

25+ data sources read at your address, not the Dexter average

How we know this about Dexter

The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this town’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Dexter’s own record; boundaries and acreage from US Census TIGER/Line 2025; the contamination records from the federal sources named in their beats above. Soil is not read at town grain anywhere on this page — there is no town-resolution survey in our data, which is why you will find no soil grid here rather than a statewide one wearing a local label. The resolution ledger below names every figure this page inherited.

Common questions about Dexter

When does frost risk typically end in Dexter?

The last hard freeze (28°F) in Dexter typically lands around Apr 25, per NOAA 1991–2020 climate normals — earlier than the light-frost dates most charts quote. That marks the hard freeze, not the last light frost — lighter frosts keep biting past it, which is why tender transplants here wait until about May 16.

When is the first frost in Dexter?

The first hard freeze (28°F) in Dexter typically arrives around Oct 13, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 29, so the watching starts about Sep 13 — about 171 days after the spring freeze cleared.

How long is the growing season in Dexter?

Measured between 28°F hard freezes, Dexter sees about 171 frost-free days — roughly Apr 25 through Oct 13, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 16 to Sep 29, about 136 days.

Is the soil safe to grow vegetables in Dexter?

The federal record around Dexter is a meaningful one — 89 documented sites, mostly Underground Storage Tanks entries (55), the nearest Underground Storage Tanks record about 0.1 miles out — so a soil test before new food beds is a sensible precaution here, not a reason to hold back from growing. Remember that proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what sits where.

How do I protect my plants from frost in Dexter?

From about Sep 13 the job here turns from planting to protecting — the last start even a 30-day crop can finish. As the season closes around the first 28°F hard freeze near Oct 13 (NOAA 1991–2020 climate normals), three moves buy time: row cover or an old sheet over tender plants on still, clear nights; water the soil the afternoon before a freeze, so it holds warmth overnight; and harvest tomatoes, peppers and basil before Oct 13. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.

Everything above is measured at Dexter's scale — its 5a band and its 171-day season. Your yard writes its own version of Dexter's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.

What this page reads at Dexter’s own scale

7 of the readings below were taken at Dexter's own scale — its own ~171-day season between 28°F freezes, the 3,022 acres it covers and 89 documented sites around it; 4 are borrowed from a wider read, named and linked below.

Measured here

  • Dexter's own USDA hardiness band, zones 5aUSDA PHZM 2023
  • Dexter's own 28°F hard-freeze dates, about Apr 25 and Oct 13 and the ~171-day span between themNOAA 1991–2020 Climate Normals
  • 89 documented contamination sites on the federal record near Dexter, the closest Underground Storage Tanks record about 0.1 miles out from the town centreFederal environmental registers
  • Dexter's boundary and the 3,022 acres inside itUS Census TIGER/Line 2025
  • Which of 1,086 plants clear zones 5a and a ~171-day seasonGrowable Ground crop-matching engine
  • The ecoregion at Dexter's own centroid, the Acadian Plains and HillsUS EPA Level III Ecoregions
  • A documented spotted-lanternfly record within reach of Dexterlydemapr (De Bona & Helmus), 10 km survey lattice

Inherited from a wider read

  • Soil character — no town-scale survey exists, so Dexter's 3,022 acres read through its county's SSURGO summaryfrom Penobscot County
  • Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Penobscot County
  • The growing challenges every Maine grower plans around — written at state scale, so they stay on the state guidefrom Maine
  • Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Penobscot County

What this page can’t tell you

  • The soil pH, drainage, sun hours, and frost pockets on any one lot among Dexter's 3,022 acreswhy one lot differs from the next
  • Which side of Dexter you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 3,022 acresreading your own microclimate
  • How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.1 miles out, measured from the town centrehow we read the record
  • Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — measured at your address, and averaged away by any Dexter-wide figureread your own land
The next step finer is your own address

More in Maine

Wider growing context

What grows across Maine

Dexter sits outside our named growing regions, so Maine as a whole is its closest context here.