Rich County, in Utah, sits in USDA hardiness zone 4b — a zone band wide enough that plant choice, not possibility, is the interesting question.
Reliable performers under these conditions include cherry, tomato, sego lily, and blue spruce; what your own ground favors still comes down to its soil, sun, and drainage.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Rich County holds more than one microclimate.
Soils and elevations shift across Rich 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.
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Quick Facts
USDA Zones
4b
Last Hard Freeze (28°F)
May 8
County normal — light frosts run a few weeks later
First Hard Freeze (28°F)
Oct 3
County normal — light frosts arrive a few weeks earlier
County Area
658K acres
Hardiness Zone Range
Zone maps are averages across Rich County. Your yard's slope, trees, and frost pockets shift what actually grows — see your land's exact reading.
Soil in Rich County
Across Rich County, the ground is predominantly Mollisols, where Pancheri, Kearl, and Duckree are the most extensive named soil series. The soil is generally well drained with a loam surface. Topsoil pH runs about 7.5–8.2, slightly alkaline. Rainfall drains through hydrologic group B soils.
Soil order
Mollisols
Drainage
Well drained
Hydric soils
3%
Soil still varies lot by lot — soil types explained.
What Grows in Rich County
Plants matched to Rich County's USDA zones 4b — each links to its full growing profile.
Is it too late to plant in Rich County?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Apr 10; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 8 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 3 — long-season crops need about 90 days of runway, quick greens only 30. In a season this compact, fast finishers and cold-hardy greens do the late work, and garlic tucked in before the freeze repays you next summer.
Growing Challenges in Utah
What an experienced grower plans around here — each one has a move.
Very low rainfall — irrigation essential
Design the drip system before the beds — with mulch over it, high-desert ground grows on a fraction of the water you'd guess.
Alkaline soils (pH 7.5-8.5) limit many species
A soil test pins your actual pH — adapted species take the ground, acid-lovers take containers, nothing is off the table.
High altitude frost risk in mountain valleys
Mountain valleys trade on frost dates, not zone — know your real window and keep row covers close in the shoulder weeks.
For cultivar selection, pest pressure, and planting-time guidance specific to Utah, the Utah State University Extension is the authoritative local source.
Safe to Grow Here?
What the federal record shows across Rich County — and how to grow with it.
We checked the federal record across Rich County — 26 documented sites across 3 of the 9 source types we track.
The most significant on record: 5 mining sites. Historic and active mines that may leach heavy metals like arsenic, lead, and cadmium.
The federal record across Rich 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.
Severity Distribution
across Rich County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Rich County, two things run higher than the national average — Mining (5 sites) and Underground Storage Tanks (19 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.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check your specific parcel in Rich 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
Rich County Average
- ●USDA Zones 4b
- ●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 Rich County
Pull a site-specific report for your exact address in Rich County, Utah — 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 Rich County, Utah
- USDA Hardiness Zones: 4b (USDA PHZM 2023)
- Last Hard Freeze (28°F): May 8 (county normal, NOAA 1991–2020 Climate Normals — light frosts can follow for a few weeks)
- First Hard Freeze (28°F): Oct 3 (county normal, NOAA 1991–2020 Climate Normals — light frosts can arrive a few weeks earlier)
- Days Between Hard Freezes: ~148 (county normal, NOAA 1991–2020 Climate Normals)
- County Land Area: 658K 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 Rich 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 Rich County, Utah?
Rich County sits in USDA hardiness zone 4b, 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 Rich County?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Apr 10; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 8 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 3 — long-season crops need about 90 days of runway, quick greens only 30. In a season this compact, fast finishers and cold-hardy greens do the late work, and garlic tucked in before the freeze repays you next summer.
When does frost risk typically end in Rich County?
The last hard freeze (28°F) in Rich County typically lands around May 8, 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 Rich County?
Measured between 28°F hard freezes, Rich County sees about 148 frost-free days — roughly May 8 through Oct 3, 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 Rich County?
Rich County's zone 4b supports a wide range — strong performers include Cherry, Tomato, Sego Lily, and Blue Spruce. 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 Rich County, really?
Officially, Rich County sits in USDA zone 4b (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 Rich County?
The federal record around Rich County shows 26 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.
How do gardeners stretch the season in Rich County?
With about 148 frost-free days between hard freezes, Rich County rewards the classic extension moves: floating row cover buys roughly two to four extra weeks at each shoulder, cold frames and low tunnels more, and quick-maturing varieties make the arithmetic work. Starting transplants indoors ahead of the May 8 hard-freeze normal stretches the season without touching the calendar.
Everything on this page is a Rich 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 Utah's frost window, season length, and soil profile against the plant's real requirements.