What Grows in Millard County, Utah

USDA Zones 6a · 4.3M acres

Millard County, in Utah, sits in USDA hardiness zone 6a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.

These conditions suit cherry, peach, tomato, and sego lily — a starting list any specific site will trim or extend with its own soil, sun, and drainage.

Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals

Score your parcel · free

Millard County holds more than one microclimate.

Soils and elevations shift across Millard 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

6a

Last Hard Freeze (28°F)

Apr 4

County normal — light frosts run a few weeks later

First Hard Freeze (28°F)

Oct 28

County normal — light frosts arrive a few weeks earlier

County Area

4.3M acres

Hardiness Zone Range

6a6a
3a (Cold)13b (Hot)

Zone maps are averages across Millard County. Your yard's slope, trees, and frost pockets shift what actually grows — see your land's exact reading.

Soil in Millard County

Across Millard County, the ground is predominantly Entisols, where Uvada, Yenrab, and Abraham are the most extensive named soil series. The soil is generally well drained with a silt loam surface. Topsoil pH runs about 8.2–8.8, strongly alkaline. Rainfall drains through hydrologic group D soils.

Soil order

Entisols

Drainage

Well drained

Hydric soils

14%

Soil still varies lot by lot — soil types explained.

Is it too late to plant in Millard County?

Rarely: the season closes in stages, not all at once, and each stage has its crops. 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 28 — long-season crops need about 90 days of runway, quick greens only 30. There is slack in a calendar like this — late plantings, second rounds of favorites, and a fall bench that keeps beds working.

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 Millard County — and how to grow with it.

Federal record: High

We checked the federal record across Millard County536 documented sites across 7 of the 9 source types we track.

The most significant on record: 6 Toxics Release Inventory facilities. Active industrial facilities reporting chemical releases to air, water, and land.

Millard County carries one of the heavier federal records we track — and that's not a verdict on your yard. Proximity to a documented site is information, not a diagnosis: nothing here says any particular parcel is affected. It does earn one concrete step — before food beds go in the ground, a professional soil test tells you exactly what you're working with, and raised beds with clean imported soil grow well almost anywhere in the meantime.

Sources: EPA, USGS1.8M 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.

Total Sites

536

across Millard County

Risk Level

High

Highest-severity

6 Toxics Release Inventory facilities

Severity Distribution

across Millard County

High20Moderate383Low133

Highest-Severity Sites

Arbroath Mine
Mining Sites · Past Producer
Arbroath Mine
Mining Sites · Past Producer
Blue Bell Mine
Mining Sites · Past Producer
Blue Bell Mine
Mining Sites · Past Producer
Delta City
PFAS Sampling · PFAS Detected

A note from Gnorman

What an experienced grower watches for around here

In and around Millard County, two things run higher than the national average — CAFO (27 sites) and Nitrate (326 sites). That's not a problem with your land — it's information about it.

CAFO: CAFOs pose a different contamination profile than chemical sources.

Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.

Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.

Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).

Free Report

Check your specific parcel in Millard 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:

Your soil pHYour frost-free daysYour sun & shade

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

Millard County Average

  • USDA Zones 6a
  • 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

Free Report

Read your parcel in Millard County

Pull a site-specific report for your exact address in Millard County, Utah — soil, sun, drainage, frost risk, and scored plant recommendations.

Three things about your exact spot that zone averages miss:

Your soil pHYour frost-free daysYour sun & shade

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 Millard County, Utah

  • USDA Hardiness Zones: 6a (USDA PHZM 2023)
  • Last Hard Freeze (28°F): Apr 4 (county normal, NOAA 1991–2020 Climate Normals — light frosts can follow for a few weeks)
  • First Hard Freeze (28°F): Oct 28 (county normal, NOAA 1991–2020 Climate Normals — light frosts can arrive a few weeks earlier)
  • Days Between Hard Freezes: ~207 (county normal, NOAA 1991–2020 Climate Normals)
  • County Land Area: 4.3M 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 Millard 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 Millard County, Utah?

Millard County sits in USDA hardiness zone 6a, 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 Millard County?

Rarely: the season closes in stages, not all at once, and each stage has its crops. 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 28 — long-season crops need about 90 days of runway, quick greens only 30. There is slack in a calendar like this — late plantings, second rounds of favorites, and a fall bench that keeps beds working.

When does frost risk typically end in Millard County?

The last hard freeze (28°F) in Millard County typically lands around Apr 4, 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 Millard County?

Measured between 28°F hard freezes, Millard County sees about 207 frost-free days — roughly Apr 4 through Oct 28, 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 Millard County?

Millard County's zone 6a supports a wide range — strong performers include Cherry, Peach, 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 Millard County, really?

Officially, Millard County sits in USDA zone 6a (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 Millard County?

The federal record around Millard County runs heavier than most — 536 documented sites — so test the soil before planting food in the ground, and raised beds with clean imported soil grow well in the meantime. Even here, proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what's recorded and where.

Just moved to Millard County — what should I know before planting?

Start with three facts. Millard County sits in USDA zone 6a, which sets what survives winter; the last 28°F hard freeze typically clears around Apr 4, with about 207 frost-free days to work with (NOAA 1991–2020 climate normals); and 536 documented sites sit on the federal record here, so a soil test before food beds is the smart first step. From there, matching plants to your actual soil and sun is the fun part.

Everything on this page is a Millard 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.