Viborg, South Dakota, sits in USDA hardiness zone 5a — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
Among the crops suited to this profile: cabbage, cranberry, lavender, and collard greens. The site-level story — soil, sun, drainage — decides the rest.
Even in Viborg, 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 Viborg 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 Viborg — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Viborg — the short answer
Viborg, South Dakota: USDA zone 5a, about 179 days between hard freezes, across 332 acres of city.
- USDA zone
- 5a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 20
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 16
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~179
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 332 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 5a is Viborg's average, not your lot's — a low corner or a tree line moves it. Against Viborg's 179-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Viborg
Each reading below is measured for Viborg itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredViborg runs about 179 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
MeasuredViborg sits in USDA hardiness zone 5a.
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 Viborg is in
Viborg sits in the Northern Glaciated Plains — EPA Level III, inside the wider Great Plains. That is read at Viborg's own centroid rather than borrowed from Turner County.
What Grows in Viborg
Every plant below cleared Viborg's own zone 5a and its 179-day season. Each card opens that plant's South Dakota profile. How we score.
Is it too late to plant in Viborg?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Mar 23; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 20 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 16 — long-season crops need about 90 days of runway, quick greens only 30. Late in the year the fall bench takes over — quick greens, radishes, and garlic that repays you next summer.
What's on the federal record near Viborg
Closest first, within ~10 miles of Viborg. Listing isn't leaking, and distance isn't exposure.
- MICK'S SERVICEUnderground Storage Tanks · 350 ft
- TERRA INTERNATIONAL INCUnderground Storage Tanks · 450 ft
- ECONOMY OIL COUnderground Storage Tanks · 450 ft
- 97N53W35CCCCNitrate · 650 ft
- FORMER STATION SITEUnderground Storage Tanks · 650 ft
- 97N53W34DD2Nitrate · 950 ft
- PUMP-N-STUFFUnderground Storage Tanks · 1300 ft
- MILLERS FARM SERVICEUnderground Storage Tanks · 1400 ft
- 96N53W 2BCBCNitrate · 2500 ft
- 97N53W27DDDDNitrate · 0.9 mi
- 97N53W26DADCNitrate · 1.4 mi
- TOM'S SERVICEUnderground Storage Tanks · 3.4 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Viborg'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 Viborg.
Sources Checked
within ~10 miles of Viborg
Severity Distribution
within ~10 miles of Viborg
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Viborg, Nitrate runs higher than the national average — 144 sites within ~10 miles of Viborg. 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 Viborg
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 Viborg average
Your land is one point inside Viborg
Everything above resolves to Viborg as a whole — one PHZM band and one 28°F frost record, read across 332 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 Viborg Average
Viborg Average
- ●USDA Zones 5a, averaged across Viborg
- ●One soil character for all of Viborg
- ●Frost dates read at Viborg's scale: Apr 20 to Oct 16
YOUR Parcel
- ✓Your exact zone, not Viborg's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Viborg
Pull a site-specific report for your exact address in Viborg, South Dakota — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Viborg averages can't show:
We read public map data around Viborg — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Viborg average
How we know this about Viborg
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 Viborg’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 Viborg
When does frost risk typically end in Viborg?
The last hard freeze (28°F) in Viborg typically lands around Apr 20, 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 11.
When is the first frost in Viborg?
The first hard freeze (28°F) in Viborg typically arrives around Oct 16, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 2, so the watching starts about Sep 16 — about 179 days after the spring freeze cleared.
How long is the growing season in Viborg?
Measured between 28°F hard freezes, Viborg sees about 179 frost-free days — roughly Apr 20 through Oct 16, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 11 to Oct 2, about 144 days.
Is the soil safe to grow vegetables in Viborg?
The federal record around Viborg shows 171 documented sites, mostly Nitrate entries (144), the nearest Underground Storage Tanks record under a tenth of a mile 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 Viborg?
From about Sep 16 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 16 (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 16. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Viborg's scale — its 5a band and its 179-day season. Your yard writes its own version of Viborg'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 Viborg’s own scale
6 of the readings below were taken at Viborg's own scale — its own ~179-day season between 28°F freezes, the 332 acres it covers and 171 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Viborg's own USDA hardiness band, zones 5aUSDA PHZM 2023
- Viborg's own 28°F hard-freeze dates, about Apr 20 and Oct 16 and the ~179-day span between themNOAA 1991–2020 Climate Normals
- 171 documented contamination sites on the federal record near Viborg, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Viborg's boundary and the 332 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~179-day seasonGrowable Ground crop-matching engine
- The ecoregion at Viborg's own centroid, the Northern Glaciated PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Viborg's 332 acres read through its county's SSURGO summaryfrom Turner County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Turner County
- The growing challenges every South Dakota grower plans around — written at state scale, so they stay on the state guidefrom South Dakota
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Turner County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Viborg's 332 acreswhy one lot differs from the next →
- Which side of Viborg you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 332 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 Viborg-wide figureread your own land →