Firestone, Colorado, sits in USDA hardiness zone 5b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Among the crops suited to this profile: cabbage, cranberry, lavender, and collard greens. The site-level story — soil, sun, drainage — decides the rest.
Even in Firestone, 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 Firestone 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 Firestone — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Firestone — the short answer
Firestone, Colorado: USDA zone 5b, about 174 days between hard freezes, across 9K acres of town.
- USDA zone
- 5b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 21
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 12
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~174
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 9K 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 5b is Firestone's average, not your lot's — a low corner or a tree line moves it. Against Firestone's 174-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Firestone
Each reading below is measured for Firestone itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredFirestone runs about 174 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
MeasuredFirestone sits in USDA hardiness zone 5b.
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 Firestone is in
Firestone sits in the High Plains — EPA Level III, inside the wider Great Plains. That is read at Firestone's own centroid rather than borrowed from Weld County.
What Grows in Firestone
Every plant below cleared Firestone's own zone 5b and its 174-day season. Each card opens that plant's Colorado profile. How we score.
Is it too late to plant in Firestone?
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 24; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 21 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 12 — long-season crops need about 90 days of runway, quick greens only 30. The tail of the season still works: sixty-day crops into late summer, quick greens after, garlic last of all.
What's on the federal record near Firestone
Closest first, within ~10 miles of Firestone. Listing isn't leaking, and distance isn't exposure.
- WALGREENS STORE #9315Brownfields · 2500 ft
- King Soopers Fueling Facility #705Underground Storage Tanks · 0.5 mi
- KING SOOPERS 105Brownfields · 0.6 mi
- BESTWAY CONCRETE CO-LONGMONTToxics Release Inventory · 1.1 mi
- HOME DEPOT STORE #1552Brownfields · 1.2 mi
- Murphy ExpressUnderground Storage Tanks · 1.2 mi
- AMERICAN FURNITURE WAREHOUSEBrownfields · 1.3 mi
- American Furniture WarehouseUnderground Storage Tanks · 1.4 mi
- FirestoneUnderground Storage Tanks · 1.5 mi
- Tpi Petroleum IncUnderground Storage Tanks · 1.6 mi
- OPTERA COLORADO INCBrownfields · 1.7 mi
- AT&T Microwave SiteUnderground Storage Tanks · 1.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Firestone'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 Firestone.
Total Sites
509
within ~10 miles of Firestone
Risk Level
Elevated
Highest-severity
3 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Firestone
Severity Distribution
within ~10 miles of Firestone
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Firestone, two things run higher than the national average within ~10 miles of Firestone — PFAS (9 sites) and Toxics Release Inventory (45 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Check your specific parcel in Firestone
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 Firestone average
Your land is one point inside Firestone
Everything above resolves to Firestone as a whole — one PHZM band and one 28°F frost record, read across 9K 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 Firestone Average
Firestone Average
- ●USDA Zones 5b, averaged across Firestone
- ●One soil character for all of Firestone
- ●Frost dates read at Firestone's scale: Apr 21 to Oct 12
YOUR Parcel
- ✓Your exact zone, not Firestone's 5b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Firestone
Pull a site-specific report for your exact address in Firestone, Colorado — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Firestone averages can't show:
We read public map data around Firestone — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Firestone average
How we know this about Firestone
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 Firestone’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 Firestone
When does frost risk typically end in Firestone?
The last hard freeze (28°F) in Firestone typically lands around Apr 21, 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 12.
When is the first frost in Firestone?
The first hard freeze (28°F) in Firestone typically arrives around Oct 12, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 28, so the watching starts about Sep 12 — about 174 days after the spring freeze cleared.
How long is the growing season in Firestone?
Measured between 28°F hard freezes, Firestone sees about 174 frost-free days — roughly Apr 21 through Oct 12, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 12 to Sep 28, about 139 days.
Is the soil safe to grow vegetables in Firestone?
The federal record around Firestone is a meaningful one — 509 documented sites, mostly Underground Storage Tanks entries (215), the nearest Brownfields record about 0.5 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 Firestone?
From about Sep 12 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 12 (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 12. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Firestone's scale — its 5b band and its 174-day season. Your yard writes its own version of Firestone'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 Firestone’s own scale
6 of the readings below were taken at Firestone's own scale — its own ~174-day season between 28°F freezes, the 8,899 acres it covers and 509 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Firestone's own USDA hardiness band, zones 5bUSDA PHZM 2023
- Firestone's own 28°F hard-freeze dates, about Apr 21 and Oct 12 and the ~174-day span between themNOAA 1991–2020 Climate Normals
- 509 documented contamination sites on the federal record near Firestone, the closest Brownfields record about 0.5 miles out from the town centreFederal environmental registers
- Firestone's boundary and the 8,899 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5b and a ~174-day seasonGrowable Ground crop-matching engine
- The ecoregion at Firestone's own centroid, the High PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Firestone's 8,899 acres read through its county's SSURGO summaryfrom Weld County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Weld County
- The growing challenges every Colorado grower plans around — written at state scale, so they stay on the state guidefrom Colorado
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Weld County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Firestone's 8,899 acreswhy one lot differs from the next →
- Which side of Firestone you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 8,899 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.5 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 Firestone-wide figureread your own land →
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