New Plymouth, Idaho, sits in USDA hardiness zone 7a — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
A short list that earns its place here — cabbage, pawpaw, california poppy, and collard greens — with any one site's soil, sun, and drainage making the final cut.
Even in New Plymouth, 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 New Plymouth 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 New Plymouth — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
New Plymouth — the short answer
New Plymouth, Idaho: USDA zone 7a, about 205 days between hard freezes, across 440 acres of city.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 4
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 26
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~205
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 440 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 7a is New Plymouth's average, not your lot's — a low corner or a tree line moves it. Against New Plymouth's 205-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in New Plymouth
Each reading below is measured for New Plymouth itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredNew Plymouth runs about 205 days between hard freezes — a long growing season.
There is slack for succession plantings and slow-finishing crops: many vegetables can be sown twice, and the heat-lovers have time to ripen fully.
Plan a second sowing of quick crops after the first comes out, and use the fall window most gardeners let sit idle.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredNew Plymouth sits in USDA hardiness zone 7a.
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 New Plymouth is in
New Plymouth sits in the Snake River Plain — EPA Level III, inside the wider North American Deserts. That is read at New Plymouth's own centroid rather than borrowed from Payette County.
What Grows in New Plymouth
Every plant below cleared New Plymouth's own zone 7a and its 205-day season. Each card opens that plant's Idaho profile. How we score.
Is it too late to plant in New Plymouth?
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 7; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 4 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 26 — long-season crops need about 90 days of runway, quick greens only 30. With a season this long, “too late” mostly means “switch crops” — second sowings and a full fall garden are the norm, with garlic closing the year.
What's on the federal record near New Plymouth
Closest first, within ~10 miles of New Plymouth. Listing isn't leaking, and distance isn't exposure.
- LOWELL'S MINI MART INCUnderground Storage Tanks · 200 ft
- NEW PLYMOUTHUnderground Storage Tanks · 500 ft
- PAYETTE VALLEY SUPPLY INCUnderground Storage Tanks · 500 ft
- SI-WASH & LUBEUnderground Storage Tanks · 550 ft
- VILLAGE APTSUnderground Storage Tanks · 600 ft
- PIONEER ENTERPRISESUnderground Storage Tanks · 850 ft
- 07N 04W 04DAB1Nitrate · 1200 ft
- 07N 04W 03CBB1Nitrate · 2600 ft
- 07N 04W 09ACB1Nitrate · 2600 ft
- NORTHWEST CHROME NEW PLYMOUTHBrownfields · 2600 ft
- IDAHO TRANSPORTATION DEPTUnderground Storage Tanks · 1.1 mi
- AMERICAN FINE FOODS DIST CENTERBrownfields · 2.2 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from New Plymouth'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 New Plymouth.
Total Sites
331
within ~10 miles of New Plymouth
Risk Level
Elevated
Highest-severity
8 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of New Plymouth
Severity Distribution
within ~10 miles of New Plymouth
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around New Plymouth, two things run higher than the national average within ~10 miles of New Plymouth — CAFO (8 sites) and Nitrate (136 sites). That's not a problem with your land — it's information about it.
CAFO: CAFOs pose a different contamination profile than chemical sources.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in New Plymouth
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 New Plymouth average
Your land is one point inside New Plymouth
Everything above resolves to New Plymouth as a whole — one PHZM band and one 28°F frost record, read across 440 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 city 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 New Plymouth Average
New Plymouth Average
- ●USDA Zones 7a, averaged across New Plymouth
- ●One soil character for all of New Plymouth
- ●Frost dates read at New Plymouth's scale: Apr 4 to Oct 26
YOUR Parcel
- ✓Your exact zone, not New Plymouth's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in New Plymouth
Pull a site-specific report for your exact address in New Plymouth, Idaho — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that New Plymouth averages can't show:
We read public map data around New Plymouth — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the New Plymouth average
How we know this about New Plymouth
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this city’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at New Plymouth’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 city grain anywhere on this page — there is no city-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 New Plymouth
When does frost risk typically end in New Plymouth?
The last hard freeze (28°F) in New Plymouth typically lands around Apr 4, 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 Apr 25.
When is the first frost in New Plymouth?
The first hard freeze (28°F) in New Plymouth typically arrives around Oct 26, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 12, so the watching starts about Sep 26 — about 205 days after the spring freeze cleared.
How long is the growing season in New Plymouth?
Measured between 28°F hard freezes, New Plymouth sees about 205 frost-free days — roughly Apr 4 through Oct 26, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 25 to Oct 12, about 170 days.
Is the soil safe to grow vegetables in New Plymouth?
The federal record around New Plymouth is a meaningful one — 331 documented sites, mostly Underground Storage Tanks entries (144), the nearest Underground Storage Tanks record under a tenth of a mile 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 New Plymouth?
From about Sep 26 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 26 (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 26. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at New Plymouth's scale — its 7a band and its 205-day season. Your yard writes its own version of New Plymouth'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 New Plymouth’s own scale
6 of the readings below were taken at New Plymouth's own scale — its own ~205-day season between 28°F freezes, the 440 acres it covers and 331 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- New Plymouth's own USDA hardiness band, zones 7aUSDA PHZM 2023
- New Plymouth's own 28°F hard-freeze dates, about Apr 4 and Oct 26 and the ~205-day span between themNOAA 1991–2020 Climate Normals
- 331 documented contamination sites on the federal record near New Plymouth, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- New Plymouth's boundary and the 440 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~205-day seasonGrowable Ground crop-matching engine
- The ecoregion at New Plymouth's own centroid, the Snake River PlainUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so New Plymouth's 440 acres read through its county's SSURGO summaryfrom Payette County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Payette County
- The growing challenges every Idaho grower plans around — written at state scale, so they stay on the state guidefrom Idaho
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Payette County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among New Plymouth's 440 acreswhy one lot differs from the next →
- Which side of New Plymouth you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 440 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record under a tenth of a mile 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 New Plymouth-wide figureread your own land →
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