Houlton, Maine, sits in USDA hardiness zone 4b — a zone band wide enough that plant choice, not possibility, is the interesting question.
Growers here do well with cabbage, cranberry, turkish rocket, and collard greens — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Even in Houlton, 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 Houlton 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 Houlton — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Houlton — the short answer
Houlton, Maine: USDA zone 4b, about 153 days between hard freezes, across 3K acres of town.
- USDA zone
- 4b
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 7
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 7
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~153
- 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
Zone 4b is Houlton's average, not your lot's — a low corner or a tree line moves it. Against Houlton's 153-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Houlton
Each reading below is measured for Houlton itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredHoulton runs about 153 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
MeasuredHoulton sits in USDA hardiness zone 4b.
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 Houlton is in
Houlton sits in the Acadian Plains and Hills — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Houlton's own centroid rather than borrowed from Aroostook County.
What Grows in Houlton
Every plant below cleared Houlton's own zone 4b and its 153-day season. Each card opens that plant's Maine profile. How we score.
Is it too late to plant in Houlton?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Apr 9; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 7 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 7 — long-season crops need about 90 days of runway, quick greens only 30. The tail of the season still works: sixty-day crops into late summer, quick greens after, garlic last of all.
What's on the federal record near Houlton
Closest first, within ~10 miles of Houlton. Listing isn't leaking, and distance isn't exposure.
- HOULTON FARMS DAIRYUnderground Storage Tanks · 950 ft
- MADIGAN ESTATESUnderground Storage Tanks · 1200 ft
- HOULTON POLICE & FIRE BUILDINGUnderground Storage Tanks · 1300 ft
- HOULTON MAINWAYUnderground Storage Tanks · 1500 ft
- STEELSTONE INDUSTRIES INCUnderground Storage Tanks · 1700 ft
- HOULTON INTERNATIONAL AIRPORTUnderground Storage Tanks · 2200 ft
- D & S CONSTRUCTION INCUnderground Storage Tanks · 2200 ft
- GERVAIS, MARKUnderground Storage Tanks · 2200 ft
- DARRELL MCGUIRE & SONSUnderground Storage Tanks · 2200 ft
- JAMES RIVER CHIP PLANTUnderground Storage Tanks · 2200 ft
- GOUGH, LAWRENCEUnderground Storage Tanks · 2200 ft
- SIMPSON, GERALDUnderground Storage Tanks · 2200 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Houlton'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 Houlton.
Total Sites
115
within ~10 miles of Houlton
Risk Level
Moderate
Highest-severity
6 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Houlton
Severity Distribution
within ~10 miles of Houlton
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Houlton, Underground Storage Tanks runs higher than the national average — 85 sites within ~10 miles of Houlton. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check your specific parcel in Houlton
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 Houlton average
Your land is one point inside Houlton
Everything above resolves to Houlton 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 Houlton Average
Houlton Average
- ●USDA Zones 4b, averaged across Houlton
- ●One soil character for all of Houlton
- ●Frost dates read at Houlton's scale: May 7 to Oct 7
YOUR Parcel
- ✓Your exact zone, not Houlton's 4b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Houlton
Pull a site-specific report for your exact address in Houlton, Maine — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Houlton averages can't show:
We read public map data around Houlton — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Houlton average
How we know this about Houlton
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 Houlton’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 Houlton
When does frost risk typically end in Houlton?
The last hard freeze (28°F) in Houlton typically lands around May 7, 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 28.
When is the first frost in Houlton?
The first hard freeze (28°F) in Houlton typically arrives around Oct 7, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 23, so the watching starts about Sep 7 — about 153 days after the spring freeze cleared.
How long is the growing season in Houlton?
Measured between 28°F hard freezes, Houlton sees about 153 frost-free days — roughly May 7 through Oct 7, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 28 to Sep 23, about 118 days.
Is the soil safe to grow vegetables in Houlton?
The federal record around Houlton shows 115 documented sites, mostly Underground Storage Tanks entries (85), the nearest Underground Storage Tanks record about 0.2 miles out — a typical footprint for a growing area, and proximity to a documented site is information, not a diagnosis of any one yard. It's worth seeing which recorded sites sit closest to where you grow, and testing the soil before new food beds near any of them.
How do I protect my plants from frost in Houlton?
From about Sep 7 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 7 (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 7. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Houlton's scale — its 4b band and its 153-day season. Your yard writes its own version of Houlton'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 Houlton’s own scale
6 of the readings below were taken at Houlton's own scale — its own ~153-day season between 28°F freezes, the 3,364 acres it covers and 115 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Houlton's own USDA hardiness band, zones 4bUSDA PHZM 2023
- Houlton's own 28°F hard-freeze dates, about May 7 and Oct 7 and the ~153-day span between themNOAA 1991–2020 Climate Normals
- 115 documented contamination sites on the federal record near Houlton, the closest Underground Storage Tanks record about 0.2 miles out from the town centreFederal environmental registers
- Houlton's boundary and the 3,364 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4b and a ~153-day seasonGrowable Ground crop-matching engine
- The ecoregion at Houlton's own centroid, the Acadian Plains and HillsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Houlton's 3,364 acres read through its county's SSURGO summaryfrom Aroostook County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Aroostook 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 Aroostook County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Houlton's 3,364 acreswhy one lot differs from the next →
- Which side of Houlton you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 3,364 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.2 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 Houlton-wide figureread your own land →
More in Maine
Growing region
Nearby growing guides