Riggins, Idaho, sits in USDA hardiness zone 7b — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
The conditions favor cabbage, prickly pear, california poppy, and collard greens, among others — though every individual site edits that list with its own soil, sun, and drainage.
Even in Riggins, 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 Riggins 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 Riggins — soil, climate, flood, and parcel records. How we handle your address.
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Riggins — the short answer
Riggins, Idaho: USDA zone 7b, about 208 days between hard freezes, across 255 acres of city.
- USDA zone
- 7b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 4
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 29
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~208
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 255 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 7b is Riggins's average, not your lot's — a low corner or a tree line moves it. Against Riggins's 208-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Riggins
Each reading below is measured for Riggins itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredRiggins runs about 208 days between hard freezes — a long growing season.
There is slack for succession plantings and slow-finishing crops: many vegetables can be sown twice, and the heat-lovers have time to ripen fully.
Plan a second sowing of quick crops after the first comes out, and use the fall window most gardeners let sit idle.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredRiggins sits in USDA hardiness zone 7b.
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 Riggins is in
Riggins sits in the Blue Mountains — EPA Level III, inside the wider Northwestern Forested Mountains. That is read at Riggins's own centroid, and it is not what its county reads: Idaho County is mostly Idaho Batholith. The wider page above you is answering a different question about different ground.
What Grows in Riggins
Every plant below cleared Riggins's own zone 7b and its 208-day season. Each card opens that plant's Idaho profile. How we score.
Is it too late to plant in Riggins?
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 Mar 7; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 4 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 29 — long-season crops need about 90 days of runway, quick greens only 30. A long window like this one runs successions deep into fall — and even its last weeks take quick greens and garlic.
What's on the federal record near Riggins
Closest first, within ~10 miles of Riggins. Listing isn't leaking, and distance isn't exposure.
- FRED J HESSUnderground Storage Tanks · 450 ft
- WOODLEYS GROCERY AND GASUnderground Storage Tanks · 550 ft
- Gem Stop #17Underground Storage Tanks · 750 ft
- SALMON RIVER INNUnderground Storage Tanks · 750 ft
- RIVER STATIONUnderground Storage Tanks · 800 ft
- DELOSS Y OR CHARLENE WORKMANUnderground Storage Tanks · 950 ft
- Riggins One StopUnderground Storage Tanks · 1800 ft
- IDAHO COUNTY ROAD DEPT (1)Underground Storage Tanks · 0.7 mi
- 24N 01E 22BCA1Nitrate · 1.0 mi
- 24N 01E 22BCC1Nitrate · 1.2 mi
- BootleggerMining · 1.5 mi
- RIGGINS ELEMENTARYUnderground Storage Tanks · 4.3 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Riggins'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 Riggins.
Sources Checked
within ~10 miles of Riggins
Severity Distribution
within ~10 miles of Riggins
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Riggins, Mining runs higher than the national average — 8 sites within ~10 miles of Riggins. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Mining: Mining sites — both historic and active — can leach heavy metals (arsenic, lead, cadmium, mercury) into soil and water for centuries after operations cease.
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Check your specific parcel in Riggins
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 Riggins average
Your land is one point inside Riggins
Everything above resolves to Riggins as a whole — one PHZM band and one 28°F frost record, read across 255 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 Riggins Average
Riggins Average
- ●USDA Zones 7b, averaged across Riggins
- ●One soil character for all of Riggins
- ●Frost dates read at Riggins's scale: Apr 4 to Oct 29
YOUR Parcel
- ✓Your exact zone, not Riggins's 7b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Riggins
Pull a site-specific report for your exact address in Riggins, Idaho — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Riggins averages can't show:
We read public map data around Riggins — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Riggins average
How we know this about Riggins
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 Riggins’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 Riggins
When does frost risk typically end in Riggins?
The last hard freeze (28°F) in Riggins typically lands around Apr 4, 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 Apr 25.
When is the first frost in Riggins?
The first hard freeze (28°F) in Riggins typically arrives around Oct 29, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 15, so the watching starts about Sep 29 — about 208 days after the spring freeze cleared.
How long is the growing season in Riggins?
Measured between 28°F hard freezes, Riggins sees about 208 frost-free days — roughly Apr 4 through Oct 29, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 25 to Oct 15, about 173 days.
Is the soil safe to grow vegetables in Riggins?
The federal record around Riggins shows 27 documented sites, mostly Underground Storage Tanks entries (15), the nearest Underground Storage Tanks 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 Riggins?
From about Sep 29 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 29 (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 29. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Riggins's scale — its 7b band and its 208-day season. Your yard writes its own version of Riggins'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 Riggins’s own scale
6 of the readings below were taken at Riggins's own scale — its own ~208-day season between 28°F freezes, the 255 acres it covers and 27 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Riggins's own USDA hardiness band, zones 7bUSDA PHZM 2023
- Riggins's own 28°F hard-freeze dates, about Apr 4 and Oct 29 and the ~208-day span between themNOAA 1991–2020 Climate Normals
- 27 documented contamination sites on the federal record near Riggins, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Riggins's boundary and the 255 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7b and a ~208-day seasonGrowable Ground crop-matching engine
- Riggins sits in the Blue Mountains — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Riggins's 255 acres read through its county's SSURGO summaryfrom Idaho County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Idaho County
- The growing challenges every Idaho grower plans around — written at state scale, so they stay on the state guidefrom Idaho
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Idaho County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Riggins's 255 acreswhy one lot differs from the next →
- Which side of Riggins you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 255 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 Riggins-wide figureread your own land →
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