St. Francis, 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.
Growers here do well with cabbage, cranberry, lavender, and collard greens — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Even in St. Francis, 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 St. Francis 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 St. Francis — soil, climate, flood, and parcel records. How we handle your address.
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St. Francis — the short answer
St. Francis, South Dakota: USDA zone 5a, about 160 days between hard freezes, across 232 acres of town.
- USDA zone
- 5a
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 3
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 10
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~160
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 232 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 St. Francis's average, not your lot's — a low corner or a tree line moves it. Against St. Francis's 160-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in St. Francis
Each reading below is measured for St. Francis itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredSt. Francis runs about 160 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
MeasuredSt. Francis 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 St. Francis is in
St. Francis sits in the Northwestern Great Plains — EPA Level III, inside the wider Great Plains. That is read at St. Francis's own centroid rather than borrowed from Todd County.
What Grows in St. Francis
Every plant below cleared St. Francis's own zone 5a and its 160-day season. Each card opens that plant's South Dakota profile. How we score.
Is it too late to plant in St. Francis?
Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. Cool-season crops can go in from around Apr 5; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 3 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 10 — 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 St. Francis
Closest first, within ~10 miles of St. Francis. Listing isn't leaking, and distance isn't exposure.
- SAINT FRANCIS INDIAN SCHOOL BUS GARAGEUnderground Storage Tanks · 450 ft
- SPRING CREEK SCHOOL DISTUnderground Storage Tanks · 700 ft
- WHITINGS CONVENIENCE STOREUnderground Storage Tanks · 750 ft
- 37N30W29CCBDNitrate · 900 ft
- 37N30W32BCBCNitrate · 2200 ft
- 37N30W29CBBDNitrate · 2400 ft
- 36N31W12DCCDNitrate · 2.6 mi
- 36N31W24AACDNitrate · 3.9 mi
- 37N30W31DABNitrate · 5.0 mi
- 36N30W13BBBBNitrate · 5.6 mi
- 36N30W12DDCDNitrate · 6.3 mi
- 38N30W34AA2Nitrate · 6.4 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from St. Francis'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 St. Francis.
Total Sites
110
within ~10 miles of St. Francis
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of St. Francis
Severity Distribution
within ~10 miles of St. Francis
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around St. Francis, Nitrate runs higher than the national average — 94 sites within ~10 miles of St. Francis. That's not a problem with your land — it's information about 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 St. Francis
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 St. Francis average
Your land is one point inside St. Francis
Everything above resolves to St. Francis as a whole — one PHZM band and one 28°F frost record, read across 232 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 St. Francis Average
St. Francis Average
- ●USDA Zones 5a, averaged across St. Francis
- ●One soil character for all of St. Francis
- ●Frost dates read at St. Francis's scale: May 3 to Oct 10
YOUR Parcel
- ✓Your exact zone, not St. Francis's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in St. Francis
Pull a site-specific report for your exact address in St. Francis, South Dakota — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that St. Francis averages can't show:
We read public map data around St. Francis — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the St. Francis average
How we know this about St. Francis
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 St. Francis’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 St. Francis
When does frost risk typically end in St. Francis?
The last hard freeze (28°F) in St. Francis typically lands around May 3, 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 24.
When is the first frost in St. Francis?
The first hard freeze (28°F) in St. Francis typically arrives around Oct 10, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 26, so the watching starts about Sep 10 — about 160 days after the spring freeze cleared.
How long is the growing season in St. Francis?
Measured between 28°F hard freezes, St. Francis sees about 160 frost-free days — roughly May 3 through Oct 10, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 24 to Sep 26, about 125 days.
Is the soil safe to grow vegetables in St. Francis?
The federal record around St. Francis is a meaningful one — 110 documented sites, mostly Nitrate entries (94), the nearest Underground Storage Tanks record under a tenth of a mile out — so a soil test before new food beds is a sensible precaution here, not a reason to hold back from growing. Remember that proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what sits where.
How do I protect my plants from frost in St. Francis?
From about Sep 10 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 10 (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 10. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at St. Francis's scale — its 5a band and its 160-day season. Your yard writes its own version of St. Francis'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 St. Francis’s own scale
6 of the readings below were taken at St. Francis's own scale — its own ~160-day season between 28°F freezes, the 232 acres it covers and 110 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- St. Francis's own USDA hardiness band, zones 5aUSDA PHZM 2023
- St. Francis's own 28°F hard-freeze dates, about May 3 and Oct 10 and the ~160-day span between themNOAA 1991–2020 Climate Normals
- 110 documented contamination sites on the federal record near St. Francis, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- St. Francis's boundary and the 232 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~160-day seasonGrowable Ground crop-matching engine
- The ecoregion at St. Francis's own centroid, the Northwestern Great PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so St. Francis's 232 acres read through its county's SSURGO summaryfrom Todd County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Todd 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 Todd County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among St. Francis's 232 acreswhy one lot differs from the next →
- Which side of St. Francis you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 232 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 St. Francis-wide figureread your own land →
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