Twin Valley, Minnesota, 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.
The conditions favor cabbage, cranberry, turkish rocket, and collard greens, among others — though every individual site edits that list with its own soil, sun, and drainage.
Even in Twin Valley, 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 Twin Valley 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 Twin Valley — soil, climate, flood, and parcel records. How we handle your address.
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Twin Valley — the short answer
Twin Valley, Minnesota: USDA zone 4a, about 168 days between hard freezes, across 547 acres of city.
- USDA zone
- 4a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 27
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 12
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~168
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 547 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 Twin Valley's average, not your lot's — a low corner or a tree line moves it. Against Twin Valley's 168-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Twin Valley
Each reading below is measured for Twin Valley itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredTwin Valley runs about 168 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
MeasuredTwin Valley 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 Twin Valley is in
Twin Valley sits in the Lake Agassiz Plain — EPA Level III, inside the wider Great Plains. That is read at Twin Valley's own centroid rather than borrowed from Norman County.
What Grows in Twin Valley
Every plant below cleared Twin Valley's own zone 4a and its 168-day season. Each card opens that plant's Minnesota profile. How we score.
Is it too late to plant in Twin Valley?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Mar 30; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 27 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 12 — long-season crops need about 90 days of runway, quick greens only 30. The tail of the season still works: sixty-day crops into late summer, quick greens after, garlic last of all.
What's on the federal record near Twin Valley
Closest first, within ~10 miles of Twin Valley. Listing isn't leaking, and distance isn't exposure.
- Community CoopUnderground Storage Tanks · 200 ft
- SANFORD CLINICBrownfields · 1000 ft
- Former Standard StationUnderground Storage Tanks · 1000 ft
- SANFORD HEALTH TWIN VALLEYBrownfields · 1000 ft
- Jerrys MobilUnderground Storage Tanks · 1100 ft
- Lerud OilUnderground Storage Tanks · 1.6 mi
- NORMAN COUNTY HIGHWAY DEPT 29Brownfields · 1.8 mi
- QUICK FEEDLOTCAFO · 4.0 mi
- RT27 144N45W23BAAABD01 0000188579Nitrate · 4.7 mi
- WAUKON DAIRYCAFO · 7.1 mi
- RT26 143N44W33DCDCDB01 0000482512Nitrate · 7.4 mi
- Farmers Union Oil CoopUnderground Storage Tanks · 7.6 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Twin Valley'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 Twin Valley.
Total Sites
32
within ~10 miles of Twin Valley
Risk Level
Low
Highest-severity
4 concentrated animal feeding operations
Sources Checked
within ~10 miles of Twin Valley
Severity Distribution
within ~10 miles of Twin Valley
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Twin Valley, two things run higher than the national average within ~10 miles of Twin Valley — CAFO (4 sites) and Nitrate (14 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 Twin Valley
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 Twin Valley average
Your land is one point inside Twin Valley
Everything above resolves to Twin Valley as a whole — one PHZM band and one 28°F frost record, read across 547 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 Twin Valley Average
Twin Valley Average
- ●USDA Zones 4a, averaged across Twin Valley
- ●One soil character for all of Twin Valley
- ●Frost dates read at Twin Valley's scale: Apr 27 to Oct 12
YOUR Parcel
- ✓Your exact zone, not Twin Valley's 4a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Twin Valley
Pull a site-specific report for your exact address in Twin Valley, Minnesota — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Twin Valley averages can't show:
We read public map data around Twin Valley — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Twin Valley average
How we know this about Twin Valley
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 Twin Valley’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 Twin Valley
When does frost risk typically end in Twin Valley?
The last hard freeze (28°F) in Twin Valley typically lands around Apr 27, 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 18.
When is the first frost in Twin Valley?
The first hard freeze (28°F) in Twin Valley typically arrives around Oct 12, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 28, so the watching starts about Sep 12 — about 168 days after the spring freeze cleared.
How long is the growing season in Twin Valley?
Measured between 28°F hard freezes, Twin Valley sees about 168 frost-free days — roughly Apr 27 through Oct 12, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 18 to Sep 28, about 133 days.
Is the soil safe to grow vegetables in Twin Valley?
The federal record around Twin Valley is light — 32 documented sites across the 9 federal source types we checked, mostly Nitrate entries (14), the nearest Underground Storage Tanks record under a tenth of a mile out — and proximity to a documented site is information, not a diagnosis of any one yard. Growing food here starts from a strong position; a soil test before new food beds settles any site-specific question.
How do I protect my plants from frost in Twin Valley?
From about Sep 12 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 12 (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 12. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Twin Valley's scale — its 4a band and its 168-day season. Your yard writes its own version of Twin Valley'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 Twin Valley’s own scale
6 of the readings below were taken at Twin Valley's own scale — its own ~168-day season between 28°F freezes, the 547 acres it covers and 32 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Twin Valley's own USDA hardiness band, zones 4aUSDA PHZM 2023
- Twin Valley's own 28°F hard-freeze dates, about Apr 27 and Oct 12 and the ~168-day span between themNOAA 1991–2020 Climate Normals
- 32 documented contamination sites on the federal record near Twin Valley, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Twin Valley's boundary and the 547 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4a and a ~168-day seasonGrowable Ground crop-matching engine
- The ecoregion at Twin Valley's own centroid, the Lake Agassiz PlainUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Twin Valley's 547 acres read through its county's SSURGO summaryfrom Norman County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Norman County
- The growing challenges every Minnesota grower plans around — written at state scale, so they stay on the state guidefrom Minnesota
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Norman County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Twin Valley's 547 acreswhy one lot differs from the next →
- Which side of Twin Valley you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 547 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 Twin Valley-wide figureread your own land →
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