Idaho Falls, Idaho, sits in USDA hardiness zone 5b — a zone band wide enough that plant choice, not possibility, is the interesting question.
The conditions favor cabbage, cranberry, lavender, and collard greens, among others — though every individual site edits that list with its own soil, sun, and drainage.
Even in Idaho Falls, 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 Idaho Falls 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 Idaho Falls — soil, climate, flood, and parcel records. How we handle your address.
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Idaho Falls — the short answer
Idaho Falls, Idaho: USDA zone 5b, about 157 days between hard freezes, across 17K acres of city.
- USDA zone
- 5b
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 3
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 7
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~157
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 17K 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 5b is Idaho Falls's average, not your lot's — a low corner or a tree line moves it. Against Idaho Falls's 157-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Idaho Falls
Each reading below is measured for Idaho Falls itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredIdaho Falls runs about 157 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
MeasuredIdaho Falls sits in USDA hardiness zone 5b.
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 Idaho Falls is in
Idaho Falls sits in the Snake River Plain — EPA Level III, inside the wider North American Deserts. That is read at Idaho Falls's own centroid, and it is not what its county reads: Bonneville County is mostly Middle Rockies. The wider page above you is answering a different question about different ground.
What Grows in Idaho Falls
Every plant below cleared Idaho Falls's own zone 5b and its 157-day season. Each card opens that plant's Idaho profile. How we score.
Is it too late to plant in Idaho Falls?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Apr 5; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 3 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 7 — 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 Idaho Falls
Closest first, within ~10 miles of Idaho Falls. Listing isn't leaking, and distance isn't exposure.
- IDAHO FALLS CITY BUILDING MAINTBrownfields · 500 ft
- 02N 38E 19DBB1Nitrate · 550 ft
- COMMON CENTS FOOD STORES #160Underground Storage Tanks · 550 ft
- GOLD MEADOW DAIRYUnderground Storage Tanks · 1100 ft
- OLD FAITHFUL BEVERAGE COUnderground Storage Tanks · 1200 ft
- BLAINE OSWALD SERVICEUnderground Storage Tanks · 1400 ft
- Ball VenturesUnderground Storage Tanks · 1600 ft
- IDAHO FALLS SECTIONUnderground Storage Tanks · 1600 ft
- IDAHO FALLS TIRE AND BATTERYUnderground Storage Tanks · 1600 ft
- Electrical WholesaleUnderground Storage Tanks · 1600 ft
- Osgood FarmUnderground Storage Tanks · 1600 ft
- RED BARON FLYING SERVICEUnderground Storage Tanks · 1600 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Idaho Falls'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 Idaho Falls.
Total Sites
545
within ~10 miles of Idaho Falls
Risk Level
Elevated
Highest-severity
17 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Idaho Falls
Severity Distribution
within ~10 miles of Idaho Falls
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Idaho Falls, Underground Storage Tanks runs higher than the national average — 382 sites within ~10 miles of Idaho Falls. That's not a problem with your land — it's information about it.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check your specific parcel in Idaho Falls
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 Idaho Falls average
Your land is one point inside Idaho Falls
Everything above resolves to Idaho Falls as a whole — one PHZM band and one 28°F frost record, read across 17K 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 Idaho Falls Average
Idaho Falls Average
- ●USDA Zones 5b, averaged across Idaho Falls
- ●One soil character for all of Idaho Falls
- ●Frost dates read at Idaho Falls's scale: May 3 to Oct 7
YOUR Parcel
- ✓Your exact zone, not Idaho Falls's 5b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Idaho Falls
Pull a site-specific report for your exact address in Idaho Falls, Idaho — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Idaho Falls averages can't show:
We read public map data around Idaho Falls — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Idaho Falls average
How we know this about Idaho Falls
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 Idaho Falls’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 Idaho Falls
When does frost risk typically end in Idaho Falls?
The last hard freeze (28°F) in Idaho Falls typically lands around May 3, 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 24.
When is the first frost in Idaho Falls?
The first hard freeze (28°F) in Idaho Falls typically arrives around Oct 7, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 23, so the watching starts about Sep 7 — about 157 days after the spring freeze cleared.
How long is the growing season in Idaho Falls?
Measured between 28°F hard freezes, Idaho Falls sees about 157 frost-free days — roughly May 3 through Oct 7, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 24 to Sep 23, about 122 days.
Is the soil safe to grow vegetables in Idaho Falls?
The federal record around Idaho Falls is a meaningful one — 545 documented sites, mostly Underground Storage Tanks entries (382), the nearest Brownfields record under a tenth of a mile out — so a soil test before new food beds is a sensible precaution here, not a reason to hold back from growing. Remember that proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what sits where.
How do I protect my plants from frost in Idaho Falls?
From about Sep 7 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 7 (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 7. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Idaho Falls's scale — its 5b band and its 157-day season. Your yard writes its own version of Idaho Falls'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 Idaho Falls’s own scale
6 of the readings below were taken at Idaho Falls's own scale — its own ~157-day season between 28°F freezes, the 17,376 acres it covers and 545 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Idaho Falls's own USDA hardiness band, zones 5bUSDA PHZM 2023
- Idaho Falls's own 28°F hard-freeze dates, about May 3 and Oct 7 and the ~157-day span between themNOAA 1991–2020 Climate Normals
- 545 documented contamination sites on the federal record near Idaho Falls, the closest Brownfields record under a tenth of a mile out from the town centreFederal environmental registers
- Idaho Falls's boundary and the 17,376 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5b and a ~157-day seasonGrowable Ground crop-matching engine
- Idaho Falls sits in the Snake River Plain — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Idaho Falls's 17,376 acres read through its county's SSURGO summaryfrom Bonneville County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Bonneville 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 Bonneville County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Idaho Falls's 17,376 acreswhy one lot differs from the next →
- Which side of Idaho Falls you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 17,376 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields 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 Idaho Falls-wide figureread your own land →