McPherson County, in South Dakota, sits in USDA hardiness zone 4b — 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.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
McPherson County holds more than one microclimate.
Soils and elevations shift across McPherson County, so your frost dates and drainage aren't the county average. 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 McPherson County — soil, climate, flood, and parcel records. How we handle your address.
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McPherson County — the short answer
McPherson County, South Dakota: USDA zone 4b, about 162 days between hard freezes, across 727K acres.
- USDA zone
- 4b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 30
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 9
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~162
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 727K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are county 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 McPherson County's average, not your lot's — a low corner or a tree line moves it. Against McPherson County's 162-day season, see what your own ground reads.
Heat in McPherson County
Across a year, McPherson County accumulates about 2,009 growing degree days above 50°F, about 417 fewer than the middle South Dakota county — ahead of 3 of South Dakota’s 66 counties. Degree days are the heat a crop actually gets to work with — more of them is more room to ripen a long-season crop before the freeze closes the window.
Grounded in PRISM Climate Group, Oregon State University — 1991–2020 monthly normals
Soil in McPherson County
Across McPherson County, the ground is predominantly Mollisols, where Williams, Bowbells, and Zahl are the most extensive named soil series. The soil is generally well drained with a loam surface. Topsoil pH runs about 6.7–7.2, neutral. Rainfall drains through hydrologic group B soils.
Soil order
Mollisols
Drainage
Well drained
Prime farmland
3%
Hydric soils
12%
Soil still varies lot by lot — soil types explained.
How the ground varies across McPherson County
The USDA soil survey maps 59% of McPherson County as well drained — but another 39% drains differently: 14% moderately well drained, 6% somewhat excessively drained.
Williams is the most extensive named soil at 29% of mapped acres, then Bowbells (12%) and Zahl (10%).
Which of them your own lot sits on is a parcel question, not a county one. Check your address for the survey at your boundary.
What this means for growing in McPherson County
Each reading below is measured for McPherson County itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Drainage
MeasuredThe dominant soils across McPherson County are well drained, in hydrologic group B — ground that drains quickly.
The upside is soil you can work early in spring and roots that never drown; the cost is that fast-draining ground dries out fast and leaches nutrients away before plants can use them.
Work in compost and mulch to hold moisture and feed, and water more often in short doses than deep and rarely.
USDA NRCS SSURGO
Surface pH
MeasuredTopsoil across McPherson County runs about pH 6.7–7.2, close to neutral.
This is the range most vegetables prefer — one correction you probably do not have to make, which is genuinely good news for a new bed.
Keep it there with compost rather than lime or sulfur, and only amend if your own soil test says otherwise.
USDA NRCS SSURGO
Season length
MeasuredMcPherson County runs about 162 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
MeasuredMcPherson County 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 McPherson County is in
McPherson County spans 2 EPA Level III ecoregions — Northwestern Glaciated Plains (80%) and Northern Glaciated Plains (20%). Which one your land falls in changes what grows wild there and how the ground behaves, and a county-wide answer cannot tell you which.
What Grows in McPherson County
We scored all 1,086 plants against McPherson County's own USDA zone 4b and its own 162-day season between hard freezes, using the same matching engine that runs a full parcel report. These cleared both. Sun, soil pH and drainage vary lot by lot — those are the parcel questions below. Each card opens that plant's South Dakota profile.
Is it too late to plant in McPherson County?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Apr 2; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 30 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 9 — 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 gets applied to farmland in McPherson County
USGS estimates 204,280 lb of Glyphosate on McPherson County farmland in 2019, its largest by weight, ahead of Acetochlor (91,028 lb) and Dicamba (32,482 lb).
Farmland across the whole county, not any one lot. Check your address for the site-by-site record.
Safe to Grow Here?
What the federal record shows across McPherson County — and how to grow with it.
We checked the federal record across McPherson County — 91 documented sites across 3 of the 9 source types we track.
The most significant on record: 1 brownfield site. Former commercial or industrial land where legacy contamination may persist.
The federal record across McPherson County is a modest one — a typical footprint for a growing area. Nothing here calls for alarm; it's worth knowing which recorded sites sit closest to where you grow, and each one on the map carries its type and location. If one turns out to be a near neighbor, a one-time soil test settles the question.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near McPherson County
Closest first, across McPherson County. Listing isn't leaking, and distance isn't exposure.
- LEES SINCLAIRUnderground Storage Tanks · 2.3 mi
- LONG LAKE COOPUnderground Storage Tanks · 5.0 mi
- MCPHERSON CO HWY DEPTUnderground Storage Tanks · 5.0 mi
- 128N69W30DDDDNitrate · 5.7 mi
- 126N70W27BCADNitrate · 6.5 mi
- 127N71W23BBBBNitrate · 8.6 mi
- 127N71W16CDDDNitrate · 10.1 mi
- 126N71W34ADDDNitrate · 10.8 mi
- 126N71W33AADNitrate · 11.5 mi
- 126N71W33BBBBNitrate · 12.1 mi
- 127N72W24AAAANitrate · 12.6 mi
- SD DEPT OF TRANSPORTATIONUnderground Storage Tanks · 13.4 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from McPherson County'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 McPherson County.
Severity Distribution
across McPherson County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around McPherson County, Nitrate runs higher than the national average — 74 sites across McPherson County. 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 McPherson County
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 McPherson County average
Your land is one point inside McPherson County
Everything above resolves to McPherson County as a whole — one PHZM band and one county frost record, read across 727K 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 county 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 county average.
Your Lot vs the McPherson County Average
McPherson County Average
- ●USDA Zones 4b, averaged across McPherson County
- ●One soil character for all of McPherson County
- ●Frost dates read at McPherson County's scale: Apr 30 to Oct 9
YOUR Parcel
- ✓Your exact zone, not McPherson County's 4b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in McPherson County
Pull a site-specific report for your exact address in McPherson County, South Dakota — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that McPherson County averages can't show:
We read public map data around McPherson County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the McPherson County average
How we know this about McPherson County
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at county grain; hard-freeze dates from NOAA 1991–2020 28°F normals at this county’s own record where one resolves, and the labelled statewide window where none does; soils from the USDA NRCS SSURGO survey, area-weighted across the county’s own map units; boundaries and acreage from US Census TIGER/Line 2025; the contamination and pesticide records from the federal sources named in their beats above. Where McPherson County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about McPherson County
When does frost risk typically end in McPherson County?
The last hard freeze (28°F) in McPherson County typically lands around Apr 30, 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 21.
How long is the growing season in McPherson County?
Measured between 28°F hard freezes, McPherson County sees about 162 frost-free days — roughly Apr 30 through Oct 9, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 21 to Sep 25, about 127 days.
Is the soil safe to grow vegetables in McPherson County?
The federal record around McPherson County shows 91 documented sites, mostly Nitrate entries (74), the nearest Underground Storage Tanks record about 2.3 miles 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.
Everything above is measured at McPherson County's scale — its 4b band and its 162-day season. Your yard writes its own version of McPherson County's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
Will It Grow Here?
Zone fit is the first question — each answer below reads South Dakota's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at McPherson County’s own scale
8 of the readings below were taken at McPherson County's own scale — its own ~162-day span between 28°F freezes, the 3 most extensive soil series mapped here and 91 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- McPherson County's own USDA hardiness band, zones 4bUSDA PHZM 2023
- McPherson County's own 28°F hard-freeze dates and its ~162-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in McPherson CountyUSDA NRCS SSURGO
- 91 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 2.3 miles outFederal environmental registers
- McPherson County's boundary and the 727,467 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4b and a ~162-day seasonGrowable Ground crop-matching engine
- The 2 ecoregions McPherson County spans, Northwestern Glaciated Plains the largestUS EPA Level III Ecoregions
- Which agricultural compounds go onto McPherson County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every South Dakota grower plans around — written at state scale, so they stay on the state guidefrom South Dakota
What this page can’t tell you
- How the season shifts across McPherson County — the ~162 days above is one reading at its centre; the 12 towns below each carry their owntowns in this county →
- The soil pH, drainage, sun hours, and frost pockets on any one lot among McPherson County's 727,467 acreswhy one lot differs from the next →
- Which of those 91 documented sites actually reaches your soil — that needs your address, the wind, and the groundwater directionhow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — none of it survives being averaged over McPherson Countyread your own land →