Hermosa, South Dakota, sits in USDA hardiness zone 5a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
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 Hermosa, 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 Hermosa 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 Hermosa — soil, climate, flood, and parcel records. How we handle your address.
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Hermosa — the short answer
Hermosa, South Dakota: USDA zone 5a, about 169 days between hard freezes, across 554 acres of town.
- USDA zone
- 5a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 29
- 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
- ~169
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 554 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 Hermosa's average, not your lot's — a low corner or a tree line moves it. Against Hermosa's 169-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Hermosa
Each reading below is measured for Hermosa itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredHermosa runs about 169 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
MeasuredHermosa 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 Hermosa is in
Hermosa sits in the Northwestern Great Plains — EPA Level III, inside the wider Great Plains. That is read at Hermosa's own centroid, and it is not what its county reads: Custer County is mostly Middle Rockies. The wider page above you is answering a different question about different ground.
What Grows in Hermosa
Every plant below cleared Hermosa's own zone 5a and its 169-day season. Each card opens that plant's South Dakota profile. How we score.
Is it too late to plant in Hermosa?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Apr 1; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 29 (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. 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 Hermosa
Closest first, within ~10 miles of Hermosa. Listing isn't leaking, and distance isn't exposure.
- CUSTER CO-HERMOSA-HWY SHOPUnderground Storage Tanks · 800 ft
- 002S08E32ACBBNitrate · 1900 ft
- 002S08E32BCBDNitrate · 0.5 mi
- FLYING JUnderground Storage Tanks · 0.5 mi
- 002S08E32BANitrate · 0.6 mi
- 002S08E32BCCANitrate · 0.6 mi
- BJ'S COUNTRY STORESUnderground Storage Tanks · 1.3 mi
- 003S07E11ABADNitrate · 3.5 mi
- 002S07E34ABBA(CU83A)Nitrate · 3.8 mi
- R.T. MUNYON CYCLE & AUTOBrownfields · 4.7 mi
- Juniper Silver MineMining · 4.9 mi
- 003S08E22ACDBNitrate · 4.9 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Hermosa'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 Hermosa.
Sources Checked
within ~10 miles of Hermosa
Severity Distribution
within ~10 miles of Hermosa
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Hermosa, two things run higher than the national average within ~10 miles of Hermosa — Mining (29 sites) and Nitrate (42 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Mining: Mining sites — both historic and active — can leach heavy metals (arsenic, lead, cadmium, mercury) into soil and water for centuries after operations cease.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Hermosa
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 Hermosa average
Your land is one point inside Hermosa
Everything above resolves to Hermosa as a whole — one PHZM band and one 28°F frost record, read across 554 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 Hermosa Average
Hermosa Average
- ●USDA Zones 5a, averaged across Hermosa
- ●One soil character for all of Hermosa
- ●Frost dates read at Hermosa's scale: Apr 29 to Oct 15
YOUR Parcel
- ✓Your exact zone, not Hermosa's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Hermosa
Pull a site-specific report for your exact address in Hermosa, South Dakota — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Hermosa averages can't show:
We read public map data around Hermosa — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Hermosa average
How we know this about Hermosa
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 Hermosa’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 Hermosa
When does frost risk typically end in Hermosa?
The last hard freeze (28°F) in Hermosa typically lands around Apr 29, 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 20.
When is the first frost in Hermosa?
The first hard freeze (28°F) in Hermosa 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 169 days after the spring freeze cleared.
How long is the growing season in Hermosa?
Measured between 28°F hard freezes, Hermosa sees about 169 frost-free days — roughly Apr 29 through Oct 15, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 20 to Oct 1, about 134 days.
Is the soil safe to grow vegetables in Hermosa?
The federal record around Hermosa shows 77 documented sites, mostly Nitrate entries (42), the nearest Underground Storage Tanks record about 0.2 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.
How do I protect my plants from frost in Hermosa?
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 Hermosa's scale — its 5a band and its 169-day season. Your yard writes its own version of Hermosa'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 Hermosa’s own scale
6 of the readings below were taken at Hermosa's own scale — its own ~169-day season between 28°F freezes, the 554 acres it covers and 77 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Hermosa's own USDA hardiness band, zones 5aUSDA PHZM 2023
- Hermosa's own 28°F hard-freeze dates, about Apr 29 and Oct 15 and the ~169-day span between themNOAA 1991–2020 Climate Normals
- 77 documented contamination sites on the federal record near Hermosa, the closest Underground Storage Tanks record about 0.2 miles out from the town centreFederal environmental registers
- Hermosa's boundary and the 554 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~169-day seasonGrowable Ground crop-matching engine
- Hermosa sits in the Northwestern Great Plains — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Hermosa's 554 acres read through its county's SSURGO summaryfrom Custer County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Custer 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 Custer County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Hermosa's 554 acreswhy one lot differs from the next →
- Which side of Hermosa you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 554 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 Hermosa-wide figureread your own land →
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