Voltaire, North Dakota, sits in USDA hardiness zone 4a — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Well-matched crops include cabbage, cranberry, turkish rocket, and collard greens, and the gap between "grows in the area" and "grows in your yard" is closed by soil, sun, and drainage.
Even in Voltaire, 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 Voltaire 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 Voltaire — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Voltaire — the short answer
Voltaire, North Dakota: USDA zone 4a, about 157 days between hard freezes, across 311 acres of city.
- USDA zone
- 4a
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 3
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 7
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~157
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 311 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 4a is Voltaire's average, not your lot's — a low corner or a tree line moves it. Against Voltaire's 157-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Voltaire
Each reading below is measured for Voltaire itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredVoltaire runs about 157 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
MeasuredVoltaire sits in USDA hardiness zone 4a.
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 Voltaire is in
Voltaire sits in the Northern Glaciated Plains — EPA Level III, inside the wider Great Plains. That is read at Voltaire's own centroid rather than borrowed from McHenry County.
What Grows in Voltaire
Every plant below cleared Voltaire's own zone 4a and its 157-day season. Each card opens that plant's North Dakota profile. How we score.
Is it too late to plant in Voltaire?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Apr 5; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 3 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 7 — 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 Voltaire
Closest first, within ~10 miles of Voltaire. Listing isn't leaking, and distance isn't exposure.
- 152-079-08BCCNitrate · 1.6 mi
- 153-079-31CACNitrate · 1.7 mi
- 153-079-31CABNitrate · 1.7 mi
- Archers Daniel Midland ProcessingUnderground Storage Tanks · 1.9 mi
- 153-079-31CBBNitrate · 2.0 mi
- Minot Air Force BaseUnderground Storage Tanks · 2.1 mi
- 153-080-36ADANitrate · 2.2 mi
- 153-079-30AAA3Nitrate · 2.4 mi
- 153-079-30AAA2Nitrate · 2.4 mi
- 153-079-30AAA1Nitrate · 2.4 mi
- 153-080-36AAC2Nitrate · 2.4 mi
- 153-080-25CDCNitrate · 2.9 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Voltaire'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 Voltaire.
Total Sites
92
within ~10 miles of Voltaire
Risk Level
Moderate
Highest-severity
1 Toxics Release Inventory facility
Sources Checked
within ~10 miles of Voltaire
Severity Distribution
within ~10 miles of Voltaire
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Voltaire, Nitrate runs higher than the national average — 64 sites within ~10 miles of Voltaire. That's not a problem with your land — it's information about it.
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 Voltaire
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 Voltaire average
Your land is one point inside Voltaire
Everything above resolves to Voltaire as a whole — one PHZM band and one 28°F frost record, read across 311 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 Voltaire Average
Voltaire Average
- ●USDA Zones 4a, averaged across Voltaire
- ●One soil character for all of Voltaire
- ●Frost dates read at Voltaire's scale: May 3 to Oct 7
YOUR Parcel
- ✓Your exact zone, not Voltaire's 4a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Voltaire
Pull a site-specific report for your exact address in Voltaire, North Dakota — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Voltaire averages can't show:
We read public map data around Voltaire — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Voltaire average
How we know this about Voltaire
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 Voltaire’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 Voltaire
When does frost risk typically end in Voltaire?
The last hard freeze (28°F) in Voltaire typically lands around May 3, 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 24.
When is the first frost in Voltaire?
The first hard freeze (28°F) in Voltaire typically arrives around Oct 7, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 23, so the watching starts about Sep 7 — about 157 days after the spring freeze cleared.
How long is the growing season in Voltaire?
Measured between 28°F hard freezes, Voltaire sees about 157 frost-free days — roughly May 3 through Oct 7, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 24 to Sep 23, about 122 days.
Is the soil safe to grow vegetables in Voltaire?
The federal record around Voltaire shows 92 documented sites, mostly Nitrate entries (64), the nearest Nitrate record about 1.6 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 Voltaire?
From about Sep 7 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 7 (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 7. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Voltaire's scale — its 4a band and its 157-day season. Your yard writes its own version of Voltaire'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 Voltaire’s own scale
6 of the readings below were taken at Voltaire's own scale — its own ~157-day season between 28°F freezes, the 311 acres it covers and 92 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Voltaire's own USDA hardiness band, zones 4aUSDA PHZM 2023
- Voltaire's own 28°F hard-freeze dates, about May 3 and Oct 7 and the ~157-day span between themNOAA 1991–2020 Climate Normals
- 92 documented contamination sites on the federal record near Voltaire, the closest Nitrate record about 1.6 miles out from the town centreFederal environmental registers
- Voltaire's boundary and the 311 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4a and a ~157-day seasonGrowable Ground crop-matching engine
- The ecoregion at Voltaire's own centroid, the Northern Glaciated PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Voltaire's 311 acres read through its county's SSURGO summaryfrom McHenry County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom McHenry County
- The growing challenges every North Dakota grower plans around — written at state scale, so they stay on the state guidefrom North Dakota
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom McHenry County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Voltaire's 311 acreswhy one lot differs from the next →
- Which side of Voltaire you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 311 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate record about 1.6 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 Voltaire-wide figureread your own land →
More in North Dakota
Wider growing context
What grows across North DakotaVoltaire sits outside our named growing regions, so North Dakota as a whole is its closest context here.