Swift Bird, South Dakota, sits in USDA hardiness zone 4b — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
A short list that earns its place here — cabbage, cranberry, turkish rocket, and collard greens — with any one site's soil, sun, and drainage making the final cut.
Even in Swift Bird, 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 Swift Bird 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 Swift Bird — soil, climate, flood, and parcel records. How we handle your address.
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Swift Bird — the short answer
Swift Bird, South Dakota: USDA zone 4b, about 171 days between hard freezes, across 314 acres of town.
- USDA zone
- 4b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 25
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 13
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~171
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 314 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 Swift Bird's average, not your lot's — a low corner or a tree line moves it. Against Swift Bird's 171-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Swift Bird
Each reading below is measured for Swift Bird itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredSwift Bird runs about 171 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
MeasuredSwift Bird 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 Swift Bird is in
Swift Bird sits in the Northwestern Great Plains — EPA Level III, inside the wider Great Plains. That is read at Swift Bird's own centroid rather than borrowed from Dewey County.
What Grows in Swift Bird
Every plant below cleared Swift Bird's own zone 4b and its 171-day season. Each card opens that plant's South Dakota profile. How we score.
Is it too late to plant in Swift Bird?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Mar 28; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 25 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 13 — long-season crops need about 90 days of runway, quick greens only 30. Even past midsummer there is room for a true fall garden here, and garlic planted near the close carries the momentum into next year.
What's on the federal record near Swift Bird
Closest first, within ~10 miles of Swift Bird. Listing isn't leaking, and distance isn't exposure.
- 118N78W31AAB2Nitrate · 5.2 mi
- WEST WHITLOCK BAIT SHOPUnderground Storage Tanks · 5.3 mi
- BOBS BAIT SHOPUnderground Storage Tanks · 5.5 mi
- SOUTH WHITLOCK RESORTUnderground Storage Tanks · 6.4 mi
- 14N29E36DBDDNitrate · 9.1 mi
Measured from Swift Bird'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 Swift Bird.
Severity Distribution
within ~10 miles of Swift Bird
Highest-Severity Sites
Know Before You Grow
- •On a private well, test for nitrates: above 10 mg/L the water needs treatment before irrigating.
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
Check your specific parcel in Swift Bird
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 Swift Bird average
Your land is one point inside Swift Bird
Everything above resolves to Swift Bird as a whole — one PHZM band and one 28°F frost record, read across 314 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 town 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 Swift Bird Average
Swift Bird Average
- ●USDA Zones 4b, averaged across Swift Bird
- ●One soil character for all of Swift Bird
- ●Frost dates read at Swift Bird's scale: Apr 25 to Oct 13
YOUR Parcel
- ✓Your exact zone, not Swift Bird's 4b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Swift Bird
Pull a site-specific report for your exact address in Swift Bird, South Dakota — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Swift Bird averages can't show:
We read public map data around Swift Bird — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Swift Bird average
How we know this about Swift Bird
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this town’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Swift Bird’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 town grain anywhere on this page — there is no town-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 Swift Bird
When does frost risk typically end in Swift Bird?
The last hard freeze (28°F) in Swift Bird typically lands around Apr 25, 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 16.
When is the first frost in Swift Bird?
The first hard freeze (28°F) in Swift Bird typically arrives around Oct 13, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 29, so the watching starts about Sep 13 — about 171 days after the spring freeze cleared.
How long is the growing season in Swift Bird?
Measured between 28°F hard freezes, Swift Bird sees about 171 frost-free days — roughly Apr 25 through Oct 13, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 16 to Sep 29, about 136 days.
Is the soil safe to grow vegetables in Swift Bird?
The federal record around Swift Bird is light — 7 documented sites across the 9 federal source types we checked, mostly Nitrate entries (4), the nearest Nitrate record about 5.2 miles 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 Swift Bird?
From about Sep 13 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 13 (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 13. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Swift Bird's scale — its 4b band and its 171-day season. Your yard writes its own version of Swift Bird'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 Swift Bird’s own scale
6 of the readings below were taken at Swift Bird's own scale — its own ~171-day season between 28°F freezes, the 314 acres it covers and 7 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Swift Bird's own USDA hardiness band, zones 4bUSDA PHZM 2023
- Swift Bird's own 28°F hard-freeze dates, about Apr 25 and Oct 13 and the ~171-day span between themNOAA 1991–2020 Climate Normals
- 7 documented contamination sites on the federal record near Swift Bird, the closest Nitrate record about 5.2 miles out from the town centreFederal environmental registers
- Swift Bird's boundary and the 314 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4b and a ~171-day seasonGrowable Ground crop-matching engine
- The ecoregion at Swift Bird's own centroid, the Northwestern Great PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Swift Bird's 314 acres read through its county's SSURGO summaryfrom Dewey County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Dewey 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 Dewey County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Swift Bird's 314 acreswhy one lot differs from the next →
- Which side of Swift Bird you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 314 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate record about 5.2 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 Swift Bird-wide figureread your own land →
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