Richardton, North Dakota, sits in USDA hardiness zone 4b — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
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 Richardton, 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 Richardton 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 Richardton — soil, climate, flood, and parcel records. How we handle your address.
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Richardton — the short answer
Richardton, North Dakota: USDA zone 4b, about 155 days between hard freezes, across 1K acres of city.
- USDA zone
- 4b
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 5
- 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
- ~155
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City 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 4b is Richardton's average, not your lot's — a low corner or a tree line moves it. Against Richardton's 155-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Richardton
Each reading below is measured for Richardton itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredRichardton runs about 155 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
MeasuredRichardton sits in USDA hardiness zone 4b.
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 Richardton is in
Richardton sits in the Northwestern Great Plains — EPA Level III, inside the wider Great Plains. That is read at Richardton's own centroid rather than borrowed from Stark County.
What Grows in Richardton
Every plant below cleared Richardton's own zone 4b and its 155-day season. Each card opens that plant's North Dakota profile. How we score.
Is it too late to plant in Richardton?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Apr 7; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 5 (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 Richardton
Closest first, within ~10 miles of Richardton. Listing isn't leaking, and distance isn't exposure.
- RICHARDTON MANUFACTURING COToxics Release Inventory · 0.8 mi
- 139-092-05DBBNitrate · 0.8 mi
- Jos Kilzer and Sons IncUnderground Storage Tanks · 0.8 mi
- Burlington Northern Railroad CompanyUnderground Storage Tanks · 0.9 mi
- 139-092-05DCANitrate · 0.9 mi
- 140-092-31CDANitrate · 1.0 mi
- 139-092-05ACDNitrate · 1.0 mi
- North Dakota State Dept of TransportationUnderground Storage Tanks · 1.0 mi
- 139-092-05DACNitrate · 1.1 mi
- 139-092-05DABNitrate · 1.1 mi
- Cenex Oil CoUnderground Storage Tanks · 1.1 mi
- 139-092-05AABNitrate · 1.2 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Richardton'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 Richardton.
Total Sites
66
within ~10 miles of Richardton
Risk Level
Moderate
Highest-severity
2 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Richardton
Severity Distribution
within ~10 miles of Richardton
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Richardton, Nitrate runs higher than the national average — 54 sites within ~10 miles of Richardton. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around 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 Richardton
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 Richardton average
Your land is one point inside Richardton
Everything above resolves to Richardton 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 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 Richardton Average
Richardton Average
- ●USDA Zones 4b, averaged across Richardton
- ●One soil character for all of Richardton
- ●Frost dates read at Richardton's scale: May 5 to Oct 7
YOUR Parcel
- ✓Your exact zone, not Richardton's 4b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Richardton
Pull a site-specific report for your exact address in Richardton, North Dakota — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Richardton averages can't show:
We read public map data around Richardton — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Richardton average
How we know this about Richardton
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 Richardton’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 Richardton
When does frost risk typically end in Richardton?
The last hard freeze (28°F) in Richardton typically lands around May 5, 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 26.
When is the first frost in Richardton?
The first hard freeze (28°F) in Richardton 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 155 days after the spring freeze cleared.
How long is the growing season in Richardton?
Measured between 28°F hard freezes, Richardton sees about 155 frost-free days — roughly May 5 through Oct 7, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 26 to Sep 23, about 120 days.
Is the soil safe to grow vegetables in Richardton?
The federal record around Richardton shows 66 documented sites, mostly Nitrate entries (54), the nearest Toxics Release Inventory record about 0.8 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 Richardton?
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 Richardton's scale — its 4b band and its 155-day season. Your yard writes its own version of Richardton'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 Richardton’s own scale
6 of the readings below were taken at Richardton's own scale — its own ~155-day season between 28°F freezes, the 1,418 acres it covers and 66 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Richardton's own USDA hardiness band, zones 4bUSDA PHZM 2023
- Richardton's own 28°F hard-freeze dates, about May 5 and Oct 7 and the ~155-day span between themNOAA 1991–2020 Climate Normals
- 66 documented contamination sites on the federal record near Richardton, the closest Toxics Release Inventory record about 0.8 miles out from the town centreFederal environmental registers
- Richardton's boundary and the 1,418 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4b and a ~155-day seasonGrowable Ground crop-matching engine
- The ecoregion at Richardton's own centroid, the Northwestern Great PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Richardton's 1,418 acres read through its county's SSURGO summaryfrom Stark County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Stark 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 Stark County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Richardton's 1,418 acreswhy one lot differs from the next →
- Which side of Richardton you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,418 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Toxics Release Inventory record about 0.8 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 Richardton-wide figureread your own land →
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