Spearfish, South Dakota, sits in USDA hardiness zone 5b — a zone band wide enough that plant choice, not possibility, is the interesting question.
On paper, cabbage, cranberry, lavender, and collard greens all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Even in Spearfish, 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 Spearfish 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 Spearfish — soil, climate, flood, and parcel records. How we handle your address.
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Spearfish — the short answer
Spearfish, South Dakota: USDA zone 5b, about 163 days between hard freezes, across 11K acres of city.
- USDA zone
- 5b
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 1
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 11
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~163
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 11K 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 5b is Spearfish's average, not your lot's — a low corner or a tree line moves it. Against Spearfish's 163-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Spearfish
Each reading below is measured for Spearfish itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredSpearfish runs about 163 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
MeasuredSpearfish sits in USDA hardiness zone 5b.
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 Spearfish is in
Spearfish sits in the Middle Rockies — EPA Level III, inside the wider Northwestern Forested Mountains. That is read at Spearfish's own centroid rather than borrowed from Lawrence County.
What Grows in Spearfish
Every plant below cleared Spearfish's own zone 5b and its 163-day season. Each card opens that plant's South Dakota profile. How we score.
Is it too late to plant in Spearfish?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Apr 3; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 1 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 11 — 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 Spearfish
Closest first, within ~10 miles of Spearfish. Listing isn't leaking, and distance isn't exposure.
- PARAMOUNT TECHNICAL PRODUCTS INCBrownfields · 0.7 mi
- YESWAY #1191Underground Storage Tanks · 0.8 mi
- WALMART SUPERCENTER #1543Brownfields · 0.8 mi
- JOHNSON FORD INC.Brownfields · 1.1 mi
- SPEEDY MARTUnderground Storage Tanks · 1.1 mi
- OEM WORLDWIDE LLCToxics Release Inventory · 1.2 mi
- MIKE'S PAINT AND BODYBrownfields · 1.2 mi
- AINSWORTH-BENNING CONST INCUnderground Storage Tanks · 1.6 mi
- MINITMANUnderground Storage Tanks · 1.6 mi
- MIKES PAINT & BODYBrownfields · 1.7 mi
- AMOCO #11Underground Storage Tanks · 1.7 mi
- BLACK HILLS AIRPORTUnderground Storage Tanks · 1.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Spearfish'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 Spearfish.
Total Sites
317
within ~10 miles of Spearfish
Risk Level
High
Highest-severity
2 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Spearfish
Severity Distribution
within ~10 miles of Spearfish
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Spearfish, Nitrate runs higher than the national average — 186 sites within ~10 miles of Spearfish. 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 Spearfish
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 Spearfish average
Your land is one point inside Spearfish
Everything above resolves to Spearfish as a whole — one PHZM band and one 28°F frost record, read across 11K 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 Spearfish Average
Spearfish Average
- ●USDA Zones 5b, averaged across Spearfish
- ●One soil character for all of Spearfish
- ●Frost dates read at Spearfish's scale: May 1 to Oct 11
YOUR Parcel
- ✓Your exact zone, not Spearfish's 5b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Spearfish
Pull a site-specific report for your exact address in Spearfish, South Dakota — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Spearfish averages can't show:
We read public map data around Spearfish — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Spearfish average
How we know this about Spearfish
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 Spearfish’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 Spearfish
When does frost risk typically end in Spearfish?
The last hard freeze (28°F) in Spearfish typically lands around May 1, 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 22.
When is the first frost in Spearfish?
The first hard freeze (28°F) in Spearfish typically arrives around Oct 11, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 27, so the watching starts about Sep 11 — about 163 days after the spring freeze cleared.
How long is the growing season in Spearfish?
Measured between 28°F hard freezes, Spearfish sees about 163 frost-free days — roughly May 1 through Oct 11, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 22 to Sep 27, about 128 days.
Is the soil safe to grow vegetables in Spearfish?
The federal record around Spearfish runs heavier than most — 317 documented sites, mostly Nitrate entries (186), the nearest Brownfields record about 0.7 miles out — so test the soil before planting food in the ground, and raised beds with clean imported soil grow well in the meantime. Even here, proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what's recorded and where.
How do I protect my plants from frost in Spearfish?
From about Sep 11 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 11 (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 11. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Spearfish's scale — its 5b band and its 163-day season. Your yard writes its own version of Spearfish'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 Spearfish’s own scale
6 of the readings below were taken at Spearfish's own scale — its own ~163-day season between 28°F freezes, the 11,053 acres it covers and 317 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Spearfish's own USDA hardiness band, zones 5bUSDA PHZM 2023
- Spearfish's own 28°F hard-freeze dates, about May 1 and Oct 11 and the ~163-day span between themNOAA 1991–2020 Climate Normals
- 317 documented contamination sites on the federal record near Spearfish, the closest Brownfields record about 0.7 miles out from the town centreFederal environmental registers
- Spearfish's boundary and the 11,053 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5b and a ~163-day seasonGrowable Ground crop-matching engine
- The ecoregion at Spearfish's own centroid, the Middle RockiesUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Spearfish's 11,053 acres read through its county's SSURGO summaryfrom Lawrence County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Lawrence 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 Lawrence County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Spearfish's 11,053 acreswhy one lot differs from the next →
- Which side of Spearfish you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 11,053 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.7 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 Spearfish-wide figureread your own land →
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