New Underwood, 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.
These conditions suit cabbage, cranberry, lavender, and collard greens — a starting list any specific site will trim or extend with its own soil, sun, and drainage.
Even in New Underwood, 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 New Underwood 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 New Underwood — soil, climate, flood, and parcel records. How we handle your address.
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New Underwood — the short answer
New Underwood, South Dakota: USDA zone 5a, about 165 days between hard freezes, across 929 acres of city.
- USDA zone
- 5a
- 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 13
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~165
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 929 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 New Underwood's average, not your lot's — a low corner or a tree line moves it. Against New Underwood's 165-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in New Underwood
Each reading below is measured for New Underwood itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredNew Underwood runs about 165 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
MeasuredNew Underwood 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 New Underwood is in
New Underwood sits in the Northwestern Great Plains — EPA Level III, inside the wider Great Plains. That is read at New Underwood's own centroid rather than borrowed from Pennington County.
What Grows in New Underwood
Every plant below cleared New Underwood's own zone 5a and its 165-day season. Each card opens that plant's South Dakota profile. How we score.
Is it too late to plant in New Underwood?
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 13 — 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's on the federal record near New Underwood
Closest first, within ~10 miles of New Underwood. Listing isn't leaking, and distance isn't exposure.
- FORMER STATE SHOP BLDGUnderground Storage Tanks · 1300 ft
- JOHNNIES CONOCOUnderground Storage Tanks · 1400 ft
- NEW UNDERWOOD SCHOOL DISTRICT 51-3Brownfields · 1600 ft
- MCGAS PROPANEUnderground Storage Tanks · 1900 ft
- LARRY GOSSARDUnderground Storage Tanks · 2500 ft
- GERMAN AUTO COMPANY - NEW UNDERWOODBrownfields · 0.5 mi
- BJ'S COUNTRY STOREUnderground Storage Tanks · 0.6 mi
- 002N11E31DBAANitrate · 0.8 mi
- 002N11E31DANitrate · 0.9 mi
- 02N10E29CB (PE-58ER)Nitrate · 5.4 mi
- I-90 & STATE ROUTE 157Underground Storage Tanks · 6.6 mi
- 001N10E06DNitrate · 6.9 mi
1 more site is on the record inside the same radius. See them on the map
Measured from New Underwood'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 New Underwood.
Sources Checked
within ~10 miles of New Underwood
Severity Distribution
within ~10 miles of New Underwood
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.
- •Near a brownfield, raised beds of imported soil give your food clean ground.
Check your specific parcel in New Underwood
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 New Underwood average
Your land is one point inside New Underwood
Everything above resolves to New Underwood as a whole — one PHZM band and one 28°F frost record, read across 929 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 New Underwood Average
New Underwood Average
- ●USDA Zones 5a, averaged across New Underwood
- ●One soil character for all of New Underwood
- ●Frost dates read at New Underwood's scale: May 1 to Oct 13
YOUR Parcel
- ✓Your exact zone, not New Underwood's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in New Underwood
Pull a site-specific report for your exact address in New Underwood, South Dakota — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that New Underwood averages can't show:
We read public map data around New Underwood — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the New Underwood average
How we know this about New Underwood
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 New Underwood’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 New Underwood
When does frost risk typically end in New Underwood?
The last hard freeze (28°F) in New Underwood 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 New Underwood?
The first hard freeze (28°F) in New Underwood 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 165 days after the spring freeze cleared.
How long is the growing season in New Underwood?
Measured between 28°F hard freezes, New Underwood sees about 165 frost-free days — roughly May 1 through Oct 13, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 22 to Sep 29, about 130 days.
Is the soil safe to grow vegetables in New Underwood?
The federal record around New Underwood is light — 18 documented sites across the 9 federal source types we checked, mostly Nitrate entries (10), the nearest Underground Storage Tanks record about 0.2 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 New Underwood?
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 New Underwood's scale — its 5a band and its 165-day season. Your yard writes its own version of New Underwood'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 New Underwood’s own scale
6 of the readings below were taken at New Underwood's own scale — its own ~165-day season between 28°F freezes, the 929 acres it covers and 18 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- New Underwood's own USDA hardiness band, zones 5aUSDA PHZM 2023
- New Underwood's own 28°F hard-freeze dates, about May 1 and Oct 13 and the ~165-day span between themNOAA 1991–2020 Climate Normals
- 18 documented contamination sites on the federal record near New Underwood, the closest Underground Storage Tanks record about 0.2 miles out from the town centreFederal environmental registers
- New Underwood's boundary and the 929 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~165-day seasonGrowable Ground crop-matching engine
- The ecoregion at New Underwood's own centroid, the Northwestern Great PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so New Underwood's 929 acres read through its county's SSURGO summaryfrom Pennington County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Pennington 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 Pennington County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among New Underwood's 929 acreswhy one lot differs from the next →
- Which side of New Underwood you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 929 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.2 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 New Underwood-wide figureread your own land →
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