Wilton, New Hampshire, sits in USDA hardiness zone 6a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Among the crops suited to this profile: cabbage, hazelnut, lavender, and collard greens. The site-level story — soil, sun, drainage — decides the rest.
Even in Wilton, 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 Wilton 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 Wilton — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Wilton — the short answer
Wilton, New Hampshire: USDA zone 6a, about 183 days between hard freezes, across 1K acres of town.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 20
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 20
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~183
- 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 6a is Wilton's average, not your lot's — a low corner or a tree line moves it. Against Wilton's 183-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Wilton
Each reading below is measured for Wilton itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredWilton runs about 183 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
MeasuredWilton sits in USDA hardiness zone 6a.
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 Wilton is in
Wilton sits in the Northeastern Highlands — EPA Level III, inside the wider Northern Forests. That is read at Wilton's own centroid rather than borrowed from Hillsborough County.
What Grows in Wilton
Every plant below cleared Wilton's own zone 6a and its 183-day season. Each card opens that plant's New Hampshire profile. How we score.
Is it too late to plant in Wilton?
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 Mar 23; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 20 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 20 — long-season crops need about 90 days of runway, quick greens only 30. Late in the year the fall bench takes over — quick greens, radishes, and garlic that repays you next summer.
Documented around Wilton
Spotted lanternfly documented 16 miles from Wilton, first recorded 2021. What to watch for.
What's on the federal record near Wilton
Closest first, within ~10 miles of Wilton. Listing isn't leaking, and distance isn't exposure.
- ALUMINUM CASTING INC (DBA GENERAL MACHINE & FOUNDRY)Toxics Release Inventory · 1200 ft
- WS PACKAGING GROUP INC FMR LABEL ARTUnderground Storage Tanks · 1700 ft
- WILTON SERVICE CENTERUnderground Storage Tanks · 1900 ft
- SPECIAL HERMETIC PRODUCTSBrownfields · 1900 ft
- WALTER E MURRAY JRUnderground Storage Tanks · 2100 ft
- ALS VARIETY STOREUnderground Storage Tanks · 2100 ft
- E. J. ABBOTT MEMORIAL TRUSTSuperfund · 0.6 mi
- DOLLAR GENERAL 20596Brownfields · 0.8 mi
- EARTHWORKS INCUnderground Storage Tanks · 0.8 mi
- MILFORD CIRCLE KUnderground Storage Tanks · 1.0 mi
- SHELDON AUTOMOTIVEUnderground Storage Tanks · 1.1 mi
- STONEYS AUTOMOTIVE INCUnderground Storage Tanks · 1.2 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Wilton'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 Wilton.
Sources Checked
within ~10 miles of Wilton
Severity Distribution
within ~10 miles of Wilton
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Wilton, two things run higher than the national average within ~10 miles of Wilton — Superfund (12 sites) and Nitrate (126 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Superfund: Superfund sites represent the most severe contamination in the federal system.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Wilton
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 Wilton average
Your land is one point inside Wilton
Everything above resolves to Wilton 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 Wilton Average
Wilton Average
- ●USDA Zones 6a, averaged across Wilton
- ●One soil character for all of Wilton
- ●Frost dates read at Wilton's scale: Apr 20 to Oct 20
YOUR Parcel
- ✓Your exact zone, not Wilton's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Wilton
Pull a site-specific report for your exact address in Wilton, New Hampshire — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Wilton averages can't show:
We read public map data around Wilton — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Wilton average
How we know this about Wilton
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 Wilton’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 Wilton
When does frost risk typically end in Wilton?
The last hard freeze (28°F) in Wilton typically lands around Apr 20, 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 11.
When is the first frost in Wilton?
The first hard freeze (28°F) in Wilton typically arrives around Oct 20, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 6, so the watching starts about Sep 20 — about 183 days after the spring freeze cleared.
How long is the growing season in Wilton?
Measured between 28°F hard freezes, Wilton sees about 183 frost-free days — roughly Apr 20 through Oct 20, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 11 to Oct 6, about 148 days.
Is the soil safe to grow vegetables in Wilton?
The federal record around Wilton is a meaningful one — 405 documented sites, mostly Underground Storage Tanks entries (156), the nearest Toxics Release Inventory record about 0.2 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 Wilton?
From about Sep 20 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 20 (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 20. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Wilton's scale — its 6a band and its 183-day season. Your yard writes its own version of Wilton'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 Wilton’s own scale
7 of the readings below were taken at Wilton's own scale — its own ~183-day season between 28°F freezes, the 1,349 acres it covers and 405 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Wilton's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Wilton's own 28°F hard-freeze dates, about Apr 20 and Oct 20 and the ~183-day span between themNOAA 1991–2020 Climate Normals
- 405 documented contamination sites on the federal record near Wilton, the closest Toxics Release Inventory record about 0.2 miles out from the town centreFederal environmental registers
- Wilton's boundary and the 1,349 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~183-day seasonGrowable Ground crop-matching engine
- The ecoregion at Wilton's own centroid, the Northeastern HighlandsUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Wiltonlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Wilton's 1,349 acres read through its county's SSURGO summaryfrom Hillsborough County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Hillsborough County
- The growing challenges every New Hampshire grower plans around — written at state scale, so they stay on the state guidefrom New Hampshire
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Hillsborough County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Wilton's 1,349 acreswhy one lot differs from the next →
- Which side of Wilton you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,349 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Toxics Release Inventory 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 Wilton-wide figureread your own land →
More in New Hampshire
Growing region
Nearby growing guides