Jackson, Wyoming, sits in USDA hardiness zone 4b — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
Growers here do well with okra, cranberry, cilantro, and zucchini — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Even in Jackson, 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 Jackson 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 Jackson — soil, climate, flood, and parcel records. How we handle your address.
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Jackson — the short answer
Jackson, Wyoming: USDA zone 4b, about 116 days between hard freezes, across 2K acres of town.
- USDA zone
- 4b
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 27
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Sep 20
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~116
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 2K 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 4b is Jackson's average, not your lot's — a low corner or a tree line moves it. Against Jackson's 116-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Jackson
Each reading below is measured for Jackson itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredJackson runs about 116 days between hard freezes — a short growing season.
Long-maturing crops like melons, sweet potatoes, and winter squash can run out of runway before the first hard freeze, ripening late or not at all.
Lead with fast-maturing varieties, and stretch the season on both ends with cold frames, low tunnels, or a greenhouse.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredJackson sits in USDA hardiness zone 4b.
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 Jackson is in
Jackson sits in the Middle Rockies — EPA Level III, inside the wider Northwestern Forested Mountains. That is read at Jackson's own centroid rather than borrowed from Teton County.
What Grows in Jackson
Every plant below cleared Jackson's own zone 4b and its 116-day season. Each card opens that plant's Wyoming profile. How we score.
Is it too late to plant in Jackson?
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 29; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 27 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Sep 20 — long-season crops need about 90 days of runway, quick greens only 30. When the window is tight, the fall moves are quick ones — baby greens, radishes, and garlic set for next season.
What's on the federal record near Jackson
Closest first, within ~10 miles of Jackson. Listing isn't leaking, and distance isn't exposure.
- 41N 116W 33CBA1Nitrate · 650 ft
- Teton County Library SiteUnderground Storage Tanks · 1100 ft
- Jackson Hole Art and Frame ShopUnderground Storage Tanks · 1400 ft
- Quality CleanersUnderground Storage Tanks · 1500 ft
- QUALITY CLEANERS INCBrownfields · 1500 ft
- JACKSON PUBLIC WORKSBrownfields · 1500 ft
- Public Works ShopUnderground Storage Tanks · 1600 ft
- Jackson Hole Distributing CompanyUnderground Storage Tanks · 1700 ft
- JACKSON SERVICE CENTERBrownfields · 1900 ft
- Cowboy MotorsUnderground Storage Tanks · 2000 ft
- Jackson Hole ChevronUnderground Storage Tanks · 2000 ft
- Teton Motors Radiator and RV RepairUnderground Storage Tanks · 2100 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Jackson'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 Jackson.
Total Sites
270
within ~10 miles of Jackson
Risk Level
Elevated
Highest-severity
1 Toxics Release Inventory facility
Sources Checked
within ~10 miles of Jackson
Severity Distribution
within ~10 miles of Jackson
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Jackson, Nitrate runs higher than the national average — 124 sites within ~10 miles of Jackson. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
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 Jackson
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 Jackson average
Your land is one point inside Jackson
Everything above resolves to Jackson as a whole — one PHZM band and one 28°F frost record, read across 2K 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 Jackson Average
Jackson Average
- ●USDA Zones 4b, averaged across Jackson
- ●One soil character for all of Jackson
- ●Frost dates read at Jackson's scale: May 27 to Sep 20
YOUR Parcel
- ✓Your exact zone, not Jackson's 4b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Jackson
Pull a site-specific report for your exact address in Jackson, Wyoming — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Jackson averages can't show:
We read public map data around Jackson — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Jackson average
How we know this about Jackson
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 Jackson’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 Jackson
When does frost risk typically end in Jackson?
The last hard freeze (28°F) in Jackson typically lands around May 27, 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 Jun 17.
When is the first frost in Jackson?
The first hard freeze (28°F) in Jackson typically arrives around Sep 20, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 6, so the watching starts about Aug 21 — about 116 days after the spring freeze cleared.
How long is the growing season in Jackson?
Measured between 28°F hard freezes, Jackson sees about 116 frost-free days — roughly May 27 through Sep 20, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Jun 17 to Sep 6, about 81 days.
Is the soil safe to grow vegetables in Jackson?
The federal record around Jackson is a meaningful one — 270 documented sites, mostly Nitrate entries (124), the nearest Nitrate record about 0.1 miles 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 gardeners stretch the season in Jackson?
With about 116 frost-free days between hard freezes, Jackson rewards the classic extension moves: floating row cover buys roughly two to four extra weeks at each shoulder — on this season that is a working window nearer 144 to 172 days — and cold frames or low tunnels buy more. Starting transplants indoors ahead of the May 27 hard-freeze normal stretches the season without touching the calendar.
Everything above is measured at Jackson's scale — its 4b band and its 116-day season. Your yard writes its own version of Jackson'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 Jackson’s own scale
6 of the readings below were taken at Jackson's own scale — its own ~116-day season between 28°F freezes, the 1,895 acres it covers and 270 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Jackson's own USDA hardiness band, zones 4bUSDA PHZM 2023
- Jackson's own 28°F hard-freeze dates, about May 27 and Sep 20 and the ~116-day span between themNOAA 1991–2020 Climate Normals
- 270 documented contamination sites on the federal record near Jackson, the closest Nitrate record about 0.1 miles out from the town centreFederal environmental registers
- Jackson's boundary and the 1,895 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 4b and a ~116-day seasonGrowable Ground crop-matching engine
- The ecoregion at Jackson's own centroid, the Middle RockiesUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Jackson's 1,895 acres read through its county's SSURGO summaryfrom Teton County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Teton County
- The growing challenges every Wyoming grower plans around — written at state scale, so they stay on the state guidefrom Wyoming
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Teton County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Jackson's 1,895 acreswhy one lot differs from the next →
- Which side of Jackson you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,895 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate record about 0.1 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 Jackson-wide figureread your own land →