East Merrimack, New Hampshire, sits in USDA hardiness zone 6a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
A short list that earns its place here — cabbage, hazelnut, lavender, and collard greens — with any one site's soil, sun, and drainage making the final cut.
Even in East Merrimack, 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 East Merrimack 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 East Merrimack — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
East Merrimack — the short answer
East Merrimack, New Hampshire: USDA zone 6a, about 196 days between hard freezes, across 2K acres of town.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 12
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 25
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~196
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 2K 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 East Merrimack's average, not your lot's — a low corner or a tree line moves it. Against East Merrimack's 196-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in East Merrimack
Each reading below is measured for East Merrimack itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredEast Merrimack runs about 196 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
MeasuredEast Merrimack 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 East Merrimack is in
East Merrimack sits in the Northeastern Coastal Zone — EPA Level III, inside the wider Eastern Temperate Forests. That is read at East Merrimack's own centroid, and it is not what its county reads: Hillsborough County is mostly Northeastern Highlands. The wider page above you is answering a different question about different ground.
What Grows in East Merrimack
Every plant below cleared East Merrimack's own zone 6a and its 196-day season. Each card opens that plant's New Hampshire profile. How we score.
Is it too late to plant in East Merrimack?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Mar 15; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 12 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 25 — 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 East Merrimack
Spotted lanternfly documented 18 miles from East Merrimack, first recorded 2022. What to watch for.
What's on the federal record near East Merrimack
Closest first, within ~10 miles of East Merrimack. Listing isn't leaking, and distance isn't exposure.
- YIELD HOUSE INCUnderground Storage Tanks · 2400 ft
- LIGHTBLOCKS MFG LLCBrownfields · 2400 ft
- JEAN'S TIRE & AUTO (MARTEL'S)Underground Storage Tanks · 2500 ft
- NASHUA CORPORATIONUnderground Storage Tanks · 2500 ft
- MERRIMACK WASTEWATER TREATMENT FACILITYUnderground Storage Tanks · 2500 ft
- GAS N GULP LLC DBA GALAXY XPRESSUnderground Storage Tanks · 2600 ft
- AUTO WORKSHOP INCBrownfields · 0.5 mi
- YIELD HOUSE INCToxics Release Inventory · 0.5 mi
- LONGA DISPOSAL AREASuperfund · 0.5 mi
- FORMER PYNENBURG'S SERVICE STATIONUnderground Storage Tanks · 0.6 mi
- LEON CALAWA JRUnderground Storage Tanks · 0.7 mi
- BRIANS AUTO REPAIR SVC COLLISION SPECIALISTBrownfields · 0.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from East Merrimack'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 East Merrimack.
Sources Checked
within ~10 miles of East Merrimack
Severity Distribution
within ~10 miles of East Merrimack
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around East Merrimack, two things run higher than the national average within ~10 miles of East Merrimack — Superfund (26 sites) and Toxics Release Inventory (128 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.
Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Check your specific parcel in East Merrimack
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 East Merrimack average
Your land is one point inside East Merrimack
Everything above resolves to East Merrimack as a whole — one PHZM band and one 28°F frost record, read across 2K 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 East Merrimack Average
East Merrimack Average
- ●USDA Zones 6a, averaged across East Merrimack
- ●One soil character for all of East Merrimack
- ●Frost dates read at East Merrimack's scale: Apr 12 to Oct 25
YOUR Parcel
- ✓Your exact zone, not East Merrimack's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in East Merrimack
Pull a site-specific report for your exact address in East Merrimack, New Hampshire — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that East Merrimack averages can't show:
We read public map data around East Merrimack — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the East Merrimack average
How we know this about East Merrimack
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 East Merrimack’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 East Merrimack
When does frost risk typically end in East Merrimack?
The last hard freeze (28°F) in East Merrimack typically lands around Apr 12, 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 3.
When is the first frost in East Merrimack?
The first hard freeze (28°F) in East Merrimack typically arrives around Oct 25, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 11, so the watching starts about Sep 25 — about 196 days after the spring freeze cleared.
How long is the growing season in East Merrimack?
Measured between 28°F hard freezes, East Merrimack sees about 196 frost-free days — roughly Apr 12 through Oct 25, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 3 to Oct 11, about 161 days.
Is the soil safe to grow vegetables in East Merrimack?
The federal record around East Merrimack runs heavier than most — 1,744 documented sites, mostly Underground Storage Tanks entries (870), the nearest Underground Storage Tanks record about 0.5 miles out — so test the soil before planting food in the ground, and raised beds with clean imported soil grow well in the meantime. Even here, proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what's recorded and where.
How do I protect my plants from frost in East Merrimack?
From about Sep 25 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 25 (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 25. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at East Merrimack's scale — its 6a band and its 196-day season. Your yard writes its own version of East Merrimack'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 East Merrimack’s own scale
7 of the readings below were taken at East Merrimack's own scale — its own ~196-day season between 28°F freezes, the 2,161 acres it covers and 1,744 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- East Merrimack's own USDA hardiness band, zones 6aUSDA PHZM 2023
- East Merrimack's own 28°F hard-freeze dates, about Apr 12 and Oct 25 and the ~196-day span between themNOAA 1991–2020 Climate Normals
- 1,744 documented contamination sites on the federal record near East Merrimack, the closest Underground Storage Tanks record about 0.5 miles out from the town centreFederal environmental registers
- East Merrimack's boundary and the 2,161 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~196-day seasonGrowable Ground crop-matching engine
- East Merrimack sits in the Northeastern Coastal Zone — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of East Merrimacklydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so East Merrimack's 2,161 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 East Merrimack's 2,161 acreswhy one lot differs from the next →
- Which side of East Merrimack you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 2,161 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.5 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 East Merrimack-wide figureread your own land →
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