Henniker, New Hampshire, sits in USDA hardiness zone 5b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Expect cabbage, cranberry, lavender, and collard greens to be strong candidates here; the deciding factors on any one parcel stay local — soil, sun, and drainage.
Even in Henniker, 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 Henniker 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 Henniker — soil, climate, flood, and parcel records. How we handle your address.
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Henniker — the short answer
Henniker, New Hampshire: USDA zone 5b, about 175 days between hard freezes, across 906 acres of town.
- USDA zone
- 5b
- 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 17
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~175
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 906 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 5b is Henniker's average, not your lot's — a low corner or a tree line moves it. Against Henniker's 175-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Henniker
Each reading below is measured for Henniker itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredHenniker runs about 175 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
MeasuredHenniker sits in USDA hardiness zone 5b.
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 Henniker is in
Henniker sits in the Northeastern Highlands — EPA Level III, inside the wider Northern Forests. That is read at Henniker's own centroid rather than borrowed from Merrimack County.
What Grows in Henniker
Every plant below cleared Henniker's own zone 5b and its 175-day season. Each card opens that plant's New Hampshire profile. How we score.
Is it too late to plant in Henniker?
Usually not — gardeners here simply switch what goes in the ground as the season moves. 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 17 — 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 Henniker
Survey cells within 31 miles of Henniker checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 32 miles off. What to watch for.
What's on the federal record near Henniker
Closest first, within ~10 miles of Henniker. Listing isn't leaking, and distance isn't exposure.
- NH DOT PS 504Underground Storage Tanks · 700 ft
- ROAD IN FRONT OF POP SCHULTZ STOREUnderground Storage Tanks · 1200 ft
- NEW ENGLAND COLLEGEUnderground Storage Tanks · 1300 ft
- AYER & GOSS INCUnderground Storage Tanks · 1800 ft
- ROWE PROPERTYUnderground Storage Tanks · 1900 ft
- HENNIKER MOBILUnderground Storage Tanks · 2500 ft
- HENNIKER PUBLIC WORKS GARAGEUnderground Storage Tanks · 0.5 mi
- HENNIKER VETERINARY HOSPITALBrownfields · 0.5 mi
- NEW ENGLAND COLLEGEBrownfields · 0.6 mi
- PATS PEAK SKI AREAUnderground Storage Tanks · 0.6 mi
- CENTRAL NH CONCRETEUnderground Storage Tanks · 0.7 mi
- HENNIKER SAND & GRAVELUnderground Storage Tanks · 0.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Henniker'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 Henniker.
Total Sites
262
within ~10 miles of Henniker
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of Henniker
Severity Distribution
within ~10 miles of Henniker
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Henniker, Nitrate runs higher than the national average — 114 sites within ~10 miles of Henniker. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Henniker
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 Henniker average
Your land is one point inside Henniker
Everything above resolves to Henniker as a whole — one PHZM band and one 28°F frost record, read across 906 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 Henniker Average
Henniker Average
- ●USDA Zones 5b, averaged across Henniker
- ●One soil character for all of Henniker
- ●Frost dates read at Henniker's scale: Apr 25 to Oct 17
YOUR Parcel
- ✓Your exact zone, not Henniker's 5b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Henniker
Pull a site-specific report for your exact address in Henniker, New Hampshire — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Henniker averages can't show:
We read public map data around Henniker — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Henniker average
How we know this about Henniker
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 Henniker’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 Henniker
When does frost risk typically end in Henniker?
The last hard freeze (28°F) in Henniker 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 Henniker?
The first hard freeze (28°F) in Henniker typically arrives around Oct 17, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 3, so the watching starts about Sep 17 — about 175 days after the spring freeze cleared.
How long is the growing season in Henniker?
Measured between 28°F hard freezes, Henniker sees about 175 frost-free days — roughly Apr 25 through Oct 17, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 16 to Oct 3, about 140 days.
Is the soil safe to grow vegetables in Henniker?
The federal record around Henniker is a meaningful one — 262 documented sites, mostly Nitrate entries (114), 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 Henniker?
From about Sep 17 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 17 (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 17. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Henniker's scale — its 5b band and its 175-day season. Your yard writes its own version of Henniker'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 Henniker’s own scale
7 of the readings below were taken at Henniker's own scale — its own ~175-day season between 28°F freezes, the 906 acres it covers and 262 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Henniker's own USDA hardiness band, zones 5bUSDA PHZM 2023
- Henniker's own 28°F hard-freeze dates, about Apr 25 and Oct 17 and the ~175-day span between themNOAA 1991–2020 Climate Normals
- 262 documented contamination sites on the federal record near Henniker, the closest Underground Storage Tanks record about 0.1 miles out from the town centreFederal environmental registers
- Henniker's boundary and the 906 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5b and a ~175-day seasonGrowable Ground crop-matching engine
- The ecoregion at Henniker's own centroid, the Northeastern HighlandsUS EPA Level III Ecoregions
- Lanternfly survey cells around Henniker checked, none carrying a detectionlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Henniker's 906 acres read through its county's SSURGO summaryfrom Merrimack County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Merrimack 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 Merrimack County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Henniker's 906 acreswhy one lot differs from the next →
- Which side of Henniker you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 906 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 Henniker-wide figureread your own land →
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