Teton County, in Idaho, 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.
Well-matched crops include potato, apple, hop, and cherry, and the gap between "grows in the area" and "grows in your yard" is closed by soil, sun, and drainage.
Teton County lies within the Snake River Plain — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Teton County holds more than one microclimate.
Soils and elevations shift across Teton County, so your frost dates and drainage aren't the county average. Enter your address and we'll score 1,112 plants against your land's actual soil, sun, and frost.
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Quick Facts
USDA Zones
5a
Last Hard Freeze (28°F)
May 6
County normal — light frosts run a few weeks later
First Hard Freeze (28°F)
Oct 6
County normal — light frosts arrive a few weeks earlier
County Area
287K acres
Hardiness Zone Range
Zone maps are averages across Teton County. Your yard's slope, trees, and frost pockets shift what actually grows — see your land's exact reading.
Soil in Teton County
Across Teton County, the ground is predominantly Mollisols, where Alpine, Koffgo, and Kucera are the most extensive named soil series. The soil is generally well drained with a silt loam surface. Topsoil pH runs about 6.1–7.4, neutral. Rainfall drains through hydrologic group C soils.
Soil order
Mollisols
Drainage
Well drained
Hydric soils
11%
Soil still varies lot by lot — soil types explained.
What Grows in Teton County
Plants matched to Teton County's USDA zones 5a — each links to its full growing profile.
Is it too late to plant in Teton County?
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 8; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 6 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 6 — 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.
Growing Challenges in Idaho
What an experienced grower plans around here — each one has a move.
Short growing season at higher elevations
At elevation, fast varieties plus a cold frame or low tunnel reliably buy back the weeks the calendar withholds.
Arid conditions require irrigation in most of the state
Drip irrigation and deep mulch are the arid-country baseline — set the water system before the plants.
Cold winter snaps can reach -30F in mountain valleys
Plant perennials for your real zone, not an optimistic one — a -30°F night finds every zone-pushed plant.
For cultivar selection, pest pressure, and planting-time guidance specific to Idaho, the University of Idaho Extension is the authoritative local source.
Safe to Grow Here?
What the federal record shows across Teton County — and how to grow with it.
We checked the federal record across Teton County — 170 documented sites across 4 of the 9 source types we track.
The most significant on record: 3 mining sites. Historic and active mines that may leach heavy metals like arsenic, lead, and cadmium.
The federal record across Teton County is a modest one — a typical footprint for a growing area. Nothing here calls for alarm; it's worth knowing which recorded sites sit closest to where you grow, and each one on the map carries its type and location. If one turns out to be a near neighbor, a one-time soil test settles the question.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
Environmental Intelligence
Understanding what's nearby helps you make informed decisions about where and how to grow.
Sources Checked
across Teton County
Severity Distribution
across Teton County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Teton County, Nitrate runs higher than the national average — 136 sites nearby. 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 Teton County
Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,112 plant recommendations.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources analyzed in seconds
Your Specific Parcel Matters
Teton County Average
- ●USDA Zones 5a
- ●Generic soil type for the area
- ●State-average frost dates
YOUR Parcel
- ✓Your exact hardiness zone
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Teton County
Pull a site-specific report for your exact address in Teton County, Idaho — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources analyzed in seconds
Key Growing Facts for Teton County, Idaho
- USDA Hardiness Zones: 5a (USDA PHZM 2023)
- Last Hard Freeze (28°F): May 6 (county normal, NOAA 1991–2020 Climate Normals — light frosts can follow for a few weeks)
- First Hard Freeze (28°F): Oct 6 (county normal, NOAA 1991–2020 Climate Normals — light frosts can arrive a few weeks earlier)
- Days Between Hard Freezes: ~153 (county normal, NOAA 1991–2020 Climate Normals)
- County Land Area: 287K acres (US Census TIGER 2025)
Zone data: USDA ARS Plant Hardiness Zone Map 2023. Climate data: NOAA NCEI. County boundaries: US Census TIGER/Line 2025.
Frost dates here are the Teton County average. Low spots and tree cover move them by days on any one yard — see your exact frost windows.
Frequently Asked Questions
What hardiness zone is Teton County, Idaho?
Teton County sits in USDA hardiness zone 5a, per the USDA Plant Hardiness Zone Map 2023. Zones reflect average annual extreme minimum temperatures from 1991–2020 weather data.
Is it too late to plant in Teton County?
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 8; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 6 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 6 — 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.
When does frost risk typically end in Teton County?
The last hard freeze (28°F) in Teton County typically lands around May 6, per NOAA 1991–2020 climate normals — an earlier marker than the light-frost dates many planting charts quote. That marks the hard freeze, not the last light frost — light frosts can still bite for a few more weeks, so tender transplants usually wait another 2–3 weeks.
How long is the growing season in Teton County?
Measured between 28°F hard freezes, Teton County sees about 153 frost-free days — roughly May 6 through Oct 6, per NOAA 1991–2020 climate normals. Tender crops get a somewhat shorter practical window, since lighter frosts reach a few weeks past the hard-freeze dates on both ends.
What vegetables grow in Teton County?
Teton County's zone 5a supports a wide range — strong performers include Potato, Apple, Hop, Cherry, and Lentil. What actually takes on any one site comes down to its soil, sun, and drainage, and we score each plant against the real conditions at your address.
Which hardiness zone is Teton County, really?
Officially, Teton County sits in USDA zone 5a (USDA PHZM 2023) — but a zone is a 30-year average of winter's coldest night across an area, and it can't see any one yard. A south-facing slope, a tree line, or a low frost pocket can shift a single site by half a zone either way, which is why neighboring gardeners often quote different numbers. We read the conditions at your exact address — soil, sun, slope, and frost — and score 1,112 plants against what's actually there.
Is the soil safe to grow vegetables in Teton County?
The federal record around Teton County shows 170 documented sites — 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.
Just moved to Teton County — what should I know before planting?
Start with three facts. Teton County sits in USDA zone 5a, which sets what survives winter; the last 28°F hard freeze typically clears around May 6, with about 153 frost-free days to work with (NOAA 1991–2020 climate normals); and 170 documented sites sit on the federal record — a typical footprint for a growing area, worth a look on the contamination map before food beds. From there, matching plants to your actual soil and sun is the fun part.
Everything on this page is a Teton County average. Your yard writes its own version — we read soil, sun, drainage, and frost at your exact address. Try it for 14 days — no card required.
Will It Grow Here?
Zone fit is the first question — each answer below reads Idaho's frost window, season length, and soil profile against the plant's real requirements.