Guilford, Maine, sits in USDA hardiness zone 5a — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Reliable performers under these conditions include cabbage, cranberry, lavender, and collard greens; what your own ground favors still comes down to its soil, sun, and drainage.
Even in Guilford, 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 Guilford 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 Guilford — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Guilford — the short answer
Guilford, Maine: USDA zone 5a, about 164 days between hard freezes, across 1K acres of town.
- USDA zone
- 5a
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 1
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 12
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~164
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 1K 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 5a is Guilford's average, not your lot's — a low corner or a tree line moves it. Against Guilford's 164-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Guilford
Each reading below is measured for Guilford itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredGuilford runs about 164 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
MeasuredGuilford 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 Guilford is in
Guilford sits in the Acadian Plains and Hills — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Guilford's own centroid, and it is not what its county reads: Piscataquis County is mostly Northeastern Highlands. The wider page above you is answering a different question about different ground.
What Grows in Guilford
Every plant below cleared Guilford's own zone 5a and its 164-day season. Each card opens that plant's Maine profile. How we score.
Is it too late to plant in Guilford?
Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. Cool-season crops can go in from around Apr 3; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 1 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 12 — 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.
What's on the federal record near Guilford
Closest first, within ~10 miles of Guilford. Listing isn't leaking, and distance isn't exposure.
- HARDWOOD PRODUCTSBrownfields · 0.6 mi
- HARWOOD PRODUCTS COUnderground Storage Tanks · 0.7 mi
- FAIRPOINT COMMUNICATIONSUnderground Storage Tanks · 0.7 mi
- JOHNSTON & HIBBARDUnderground Storage Tanks · 0.9 mi
- HERRICK BROTHERSUnderground Storage Tanks · 0.9 mi
- PARTNERSHIP CENTERUnderground Storage Tanks · 0.9 mi
- TRIANGLE SVC STATIONUnderground Storage Tanks · 0.9 mi
- TRUE TEXTILES INC - GUILFORD FACILITYToxics Release Inventory · 0.9 mi
- TRUE TEXTILES INC - GUILFORD FACILITYBrownfields · 0.9 mi
- HALEY CONSTRUCTION INCUnderground Storage Tanks · 1.1 mi
- GRANTS DAIRYUnderground Storage Tanks · 1.1 mi
- C & B QUICKSTOPUnderground Storage Tanks · 1.3 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Guilford'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 Guilford.
Total Sites
107
within ~10 miles of Guilford
Risk Level
Moderate
Highest-severity
3 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Guilford
Severity Distribution
within ~10 miles of Guilford
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Guilford, Underground Storage Tanks runs higher than the national average — 79 sites within ~10 miles of Guilford. 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 Guilford
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 Guilford average
Your land is one point inside Guilford
Everything above resolves to Guilford as a whole — one PHZM band and one 28°F frost record, read across 1K 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 Guilford Average
Guilford Average
- ●USDA Zones 5a, averaged across Guilford
- ●One soil character for all of Guilford
- ●Frost dates read at Guilford's scale: May 1 to Oct 12
YOUR Parcel
- ✓Your exact zone, not Guilford's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Guilford
Pull a site-specific report for your exact address in Guilford, Maine — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Guilford averages can't show:
We read public map data around Guilford — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Guilford average
How we know this about Guilford
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 Guilford’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 Guilford
When does frost risk typically end in Guilford?
The last hard freeze (28°F) in Guilford typically lands around May 1, 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 22.
When is the first frost in Guilford?
The first hard freeze (28°F) in Guilford typically arrives around Oct 12, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 28, so the watching starts about Sep 12 — about 164 days after the spring freeze cleared.
How long is the growing season in Guilford?
Measured between 28°F hard freezes, Guilford sees about 164 frost-free days — roughly May 1 through Oct 12, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 22 to Sep 28, about 129 days.
Is the soil safe to grow vegetables in Guilford?
The federal record around Guilford shows 107 documented sites, mostly Underground Storage Tanks entries (79), the nearest Brownfields record about 0.6 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 Guilford?
From about Sep 12 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 12 (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 12. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Guilford's scale — its 5a band and its 164-day season. Your yard writes its own version of Guilford'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 Guilford’s own scale
6 of the readings below were taken at Guilford's own scale — its own ~164-day season between 28°F freezes, the 1,228 acres it covers and 107 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Guilford's own USDA hardiness band, zones 5aUSDA PHZM 2023
- Guilford's own 28°F hard-freeze dates, about May 1 and Oct 12 and the ~164-day span between themNOAA 1991–2020 Climate Normals
- 107 documented contamination sites on the federal record near Guilford, the closest Brownfields record about 0.6 miles out from the town centreFederal environmental registers
- Guilford's boundary and the 1,228 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~164-day seasonGrowable Ground crop-matching engine
- Guilford sits in the Acadian Plains and Hills — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Guilford's 1,228 acres read through its county's SSURGO summaryfrom Piscataquis County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Piscataquis 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 Piscataquis County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Guilford's 1,228 acreswhy one lot differs from the next →
- Which side of Guilford you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,228 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.6 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 Guilford-wide figureread your own land →
More in Maine
Wider growing context
What grows across MaineGuilford sits outside our named growing regions, so Maine as a whole is its closest context here.
Nearby growing guides