Castle Dale, Utah, sits in USDA hardiness zone 6a — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
A short list that earns its place here — cabbage, blackberry, california poppy, and collard greens — with any one site's soil, sun, and drainage making the final cut.
Even in Castle Dale, 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 Castle Dale 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 Castle Dale — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Castle Dale — the short answer
Castle Dale, Utah: USDA zone 6a, about 168 days between hard freezes, across 1K acres of city.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 26
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 11
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~168
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 1K 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 6a is Castle Dale's average, not your lot's — a low corner or a tree line moves it. Against Castle Dale's 168-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Castle Dale
Each reading below is measured for Castle Dale itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredCastle Dale runs about 168 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
MeasuredCastle Dale sits in USDA hardiness zone 6a.
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 Castle Dale is in
Castle Dale sits in the Colorado Plateaus — EPA Level III, inside the wider North American Deserts. That is read at Castle Dale's own centroid rather than borrowed from Emery County.
What Grows in Castle Dale
Every plant below cleared Castle Dale's own zone 6a and its 168-day season. Each card opens that plant's Utah profile. How we score.
Is it too late to plant in Castle Dale?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Mar 29; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 26 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 11 — long-season crops need about 90 days of runway, quick greens only 30. Even past midsummer there is room for a true fall garden here, and garlic planted near the close carries the momentum into next year.
What's on the federal record near Castle Dale
Closest first, within ~10 miles of Castle Dale. Listing isn't leaking, and distance isn't exposure.
- SCHOOL BUS YARDUnderground Storage Tanks · 1600 ft
- EMERY COUNTY SHERIFF DEPARTMENTUnderground Storage Tanks · 2000 ft
- EMERY COUNTY ROAD DEPT.Underground Storage Tanks · 2000 ft
- UTAH POWER & LIGHT COMPANYUnderground Storage Tanks · 0.5 mi
- DESERET COAL TERMINALUnderground Storage Tanks · 0.7 mi
- JR's Stop N GoUnderground Storage Tanks · 0.7 mi
- TRACY'S CHEVRONUnderground Storage Tanks · 0.8 mi
- MAVERIK #260 CASTLE DALEUnderground Storage Tanks · 0.8 mi
- CASTLE DALE CITY SHOPUnderground Storage Tanks · 0.9 mi
- ORANGE RANCHUnderground Storage Tanks · 1.4 mi
- THE STOREUnderground Storage Tanks · 1.7 mi
- HERMS CAR REPAIRUnderground Storage Tanks · 1.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Castle Dale'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 Castle Dale.
Total Sites
35
within ~10 miles of Castle Dale
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of Castle Dale
Severity Distribution
within ~10 miles of Castle Dale
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Castle Dale, Underground Storage Tanks runs higher than the national average — 29 sites within ~10 miles of Castle Dale. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around 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 Castle Dale
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 Castle Dale average
Your land is one point inside Castle Dale
Everything above resolves to Castle Dale as a whole — one PHZM band and one 28°F frost record, read across 1K 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 Castle Dale Average
Castle Dale Average
- ●USDA Zones 6a, averaged across Castle Dale
- ●One soil character for all of Castle Dale
- ●Frost dates read at Castle Dale's scale: Apr 26 to Oct 11
YOUR Parcel
- ✓Your exact zone, not Castle Dale's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Castle Dale
Pull a site-specific report for your exact address in Castle Dale, Utah — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Castle Dale averages can't show:
We read public map data around Castle Dale — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Castle Dale average
How we know this about Castle Dale
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 Castle Dale’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 Castle Dale
When does frost risk typically end in Castle Dale?
The last hard freeze (28°F) in Castle Dale typically lands around Apr 26, 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 17.
When is the first frost in Castle Dale?
The first hard freeze (28°F) in Castle Dale typically arrives around Oct 11, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 27, so the watching starts about Sep 11 — about 168 days after the spring freeze cleared.
How long is the growing season in Castle Dale?
Measured between 28°F hard freezes, Castle Dale sees about 168 frost-free days — roughly Apr 26 through Oct 11, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 17 to Sep 27, about 133 days.
Is the soil safe to grow vegetables in Castle Dale?
The federal record around Castle Dale is a meaningful one — 35 documented sites, mostly Underground Storage Tanks entries (29), the nearest Underground Storage Tanks record about 0.3 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 I protect my plants from frost in Castle Dale?
From about Sep 11 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 11 (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 11. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Castle Dale's scale — its 6a band and its 168-day season. Your yard writes its own version of Castle Dale'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 Castle Dale’s own scale
6 of the readings below were taken at Castle Dale's own scale — its own ~168-day season between 28°F freezes, the 1,448 acres it covers and 35 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Castle Dale's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Castle Dale's own 28°F hard-freeze dates, about Apr 26 and Oct 11 and the ~168-day span between themNOAA 1991–2020 Climate Normals
- 35 documented contamination sites on the federal record near Castle Dale, the closest Underground Storage Tanks record about 0.3 miles out from the town centreFederal environmental registers
- Castle Dale's boundary and the 1,448 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~168-day seasonGrowable Ground crop-matching engine
- The ecoregion at Castle Dale's own centroid, the Colorado PlateausUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Castle Dale's 1,448 acres read through its county's SSURGO summaryfrom Emery County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Emery County
- The growing challenges every Utah grower plans around — written at state scale, so they stay on the state guidefrom Utah
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Emery County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Castle Dale's 1,448 acreswhy one lot differs from the next →
- Which side of Castle Dale you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,448 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.3 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 Castle Dale-wide figureread your own land →
More in Utah
Wider growing context
What grows across UtahCastle Dale sits outside our named growing regions, so Utah as a whole is its closest context here.
Nearby growing guides