Monroe, South Dakota, sits in USDA hardiness zone 5a — a zone band wide enough that plant choice, not possibility, is the interesting question.
A short list that earns its place here — cabbage, cranberry, lavender, and collard greens — with any one site's soil, sun, and drainage making the final cut.
Even in Monroe, 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 Monroe 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 Monroe — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Monroe — the short answer
Monroe, South Dakota: USDA zone 5a, about 177 days between hard freezes, across 243 acres of town.
- USDA zone
- 5a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 21
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 15
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~177
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 243 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 Monroe's average, not your lot's — a low corner or a tree line moves it. Against Monroe's 177-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Monroe
Each reading below is measured for Monroe itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredMonroe runs about 177 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
MeasuredMonroe 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 Monroe is in
Monroe sits in the Northern Glaciated Plains — EPA Level III, inside the wider Great Plains. That is read at Monroe's own centroid rather than borrowed from Turner County.
What Grows in Monroe
Every plant below cleared Monroe's own zone 5a and its 177-day season. Each card opens that plant's South Dakota profile. How we score.
Is it too late to plant in Monroe?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Mar 24; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 21 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 15 — long-season crops need about 90 days of runway, quick greens only 30. As the window narrows, the plantings just get faster — fall brassicas, then greens, then garlic to finish.
What's on the federal record near Monroe
Closest first, within ~10 miles of Monroe. Listing isn't leaking, and distance isn't exposure.
- 100N54W15BACBNitrate · 300 ft
- MONROE OIL COUnderground Storage Tanks · 550 ft
- VERASUN MARION, LLCToxics Release Inventory · 4.2 mi
- NUGEN ENERGY LLCToxics Release Inventory · 4.3 mi
- NUGEN ENERGY LLCBrownfields · 4.3 mi
- SONSTEGARD FOODSCAFO · 4.3 mi
- 99N54W 5BBAANitrate · 4.4 mi
- 99N54W 5BBCDNitrate · 4.6 mi
- RAPP CHEVROLET INCUnderground Storage Tanks · 4.6 mi
- MARION OILUnderground Storage Tanks · 4.7 mi
- 99N54W 5BCBBNitrate · 4.7 mi
- D & RUnderground Storage Tanks · 4.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Monroe'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 Monroe.
Total Sites
92
within ~10 miles of Monroe
Risk Level
Moderate
Highest-severity
2 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Monroe
Severity Distribution
within ~10 miles of Monroe
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Monroe, Nitrate runs higher than the national average — 60 sites within ~10 miles of Monroe. 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 Monroe
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 Monroe average
Your land is one point inside Monroe
Everything above resolves to Monroe as a whole — one PHZM band and one 28°F frost record, read across 243 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 Monroe Average
Monroe Average
- ●USDA Zones 5a, averaged across Monroe
- ●One soil character for all of Monroe
- ●Frost dates read at Monroe's scale: Apr 21 to Oct 15
YOUR Parcel
- ✓Your exact zone, not Monroe's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Monroe
Pull a site-specific report for your exact address in Monroe, South Dakota — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Monroe averages can't show:
We read public map data around Monroe — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Monroe average
How we know this about Monroe
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 Monroe’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 Monroe
When does frost risk typically end in Monroe?
The last hard freeze (28°F) in Monroe typically lands around Apr 21, 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 12.
When is the first frost in Monroe?
The first hard freeze (28°F) in Monroe typically arrives around Oct 15, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 1, so the watching starts about Sep 15 — about 177 days after the spring freeze cleared.
How long is the growing season in Monroe?
Measured between 28°F hard freezes, Monroe sees about 177 frost-free days — roughly Apr 21 through Oct 15, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 12 to Oct 1, about 142 days.
Is the soil safe to grow vegetables in Monroe?
The federal record around Monroe shows 92 documented sites, mostly Nitrate entries (60), the nearest Nitrate record under a tenth of a mile 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.
How do I protect my plants from frost in Monroe?
From about Sep 15 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 15 (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 15. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Monroe's scale — its 5a band and its 177-day season. Your yard writes its own version of Monroe'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 Monroe’s own scale
6 of the readings below were taken at Monroe's own scale — its own ~177-day season between 28°F freezes, the 243 acres it covers and 92 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Monroe's own USDA hardiness band, zones 5aUSDA PHZM 2023
- Monroe's own 28°F hard-freeze dates, about Apr 21 and Oct 15 and the ~177-day span between themNOAA 1991–2020 Climate Normals
- 92 documented contamination sites on the federal record near Monroe, the closest Nitrate record under a tenth of a mile out from the town centreFederal environmental registers
- Monroe's boundary and the 243 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~177-day seasonGrowable Ground crop-matching engine
- The ecoregion at Monroe's own centroid, the Northern Glaciated PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Monroe's 243 acres read through its county's SSURGO summaryfrom Turner County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Turner 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 Turner County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Monroe's 243 acreswhy one lot differs from the next →
- Which side of Monroe you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 243 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate 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 Monroe-wide figureread your own land →