Antonito, Colorado, sits in USDA hardiness zone 5a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Crops well matched to these conditions include cabbage, cranberry, lavender, and collard greens — though what thrives on any one site still turns on its specific soil, sun, and drainage.
Even in Antonito, 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 Antonito 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 Antonito — soil, climate, flood, and parcel records. How we handle your address.
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Antonito — the short answer
Antonito, Colorado: USDA zone 5a, about 138 days between hard freezes, across 273 acres of town.
- USDA zone
- 5a
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 16
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 1
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~138
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 273 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 5a is Antonito's average, not your lot's — a low corner or a tree line moves it. Against Antonito's 138-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Antonito
Each reading below is measured for Antonito itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredAntonito runs about 138 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
MeasuredAntonito sits in USDA hardiness zone 5a.
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 Antonito is in
Antonito sits in the Arizona/New Mexico Plateau — EPA Level III, inside the wider North American Deserts. That is read at Antonito's own centroid rather than borrowed from Conejos County.
What Grows in Antonito
Every plant below cleared Antonito's own zone 5a and its 138-day season. Each card opens that plant's Colorado profile. How we score.
Is it too late to plant in Antonito?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Apr 18; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 16 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 1 — long-season crops need about 90 days of runway, quick greens only 30. Even here the calendar’s edges hold value: thirty-day greens late in the window, then garlic and a rested bed for spring.
What's on the federal record near Antonito
Closest first, within ~10 miles of Antonito. Listing isn't leaking, and distance isn't exposure.
- Cliff Brice StationsUnderground Storage Tanks · 800 ft
- UPRR Antonito YardUnderground Storage Tanks · 900 ft
- Antonito SchoolsUnderground Storage Tanks · 900 ft
- Auto Care Center / Food MartUnderground Storage Tanks · 1100 ft
- R O G IncUnderground Storage Tanks · 1200 ft
- FAMILY DOLLAR #8819Brownfields · 1400 ft
- Curtis Motor CoUnderground Storage Tanks · 1600 ft
- Antonito AmocoUnderground Storage Tanks · 0.5 mi
- Manville Products CorpUnderground Storage Tanks · 0.6 mi
- Grefco IncUnderground Storage Tanks · 0.6 mi
- CDOT Antonito ConejosUnderground Storage Tanks · 0.8 mi
- Conejos CountyUnderground Storage Tanks · 1.0 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Antonito'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 Antonito.
Total Sites
35
within ~10 miles of Antonito
Risk Level
Low
Highest-severity
1 Toxics Release Inventory facility
Sources Checked
within ~10 miles of Antonito
Severity Distribution
within ~10 miles of Antonito
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Antonito, Nitrate runs higher than the national average — 14 sites within ~10 miles of Antonito. That's not a problem with your land — it's information about it.
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 Antonito
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 Antonito average
Your land is one point inside Antonito
Everything above resolves to Antonito as a whole — one PHZM band and one 28°F frost record, read across 273 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 Antonito Average
Antonito Average
- ●USDA Zones 5a, averaged across Antonito
- ●One soil character for all of Antonito
- ●Frost dates read at Antonito's scale: May 16 to Oct 1
YOUR Parcel
- ✓Your exact zone, not Antonito's 5a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Antonito
Pull a site-specific report for your exact address in Antonito, Colorado — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Antonito averages can't show:
We read public map data around Antonito — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Antonito average
How we know this about Antonito
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 Antonito’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 Antonito
When does frost risk typically end in Antonito?
The last hard freeze (28°F) in Antonito typically lands around May 16, 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 6.
When is the first frost in Antonito?
The first hard freeze (28°F) in Antonito typically arrives around Oct 1, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 17, so the watching starts about Sep 1 — about 138 days after the spring freeze cleared.
How long is the growing season in Antonito?
Measured between 28°F hard freezes, Antonito sees about 138 frost-free days — roughly May 16 through Oct 1, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Jun 6 to Sep 17, about 103 days.
Is the soil safe to grow vegetables in Antonito?
The federal record around Antonito is light — 35 documented sites across the 9 federal source types we checked, mostly Underground Storage Tanks entries (17), the nearest Underground Storage Tanks record about 0.2 miles out — and proximity to a documented site is information, not a diagnosis of any one yard. Growing food here starts from a strong position; a soil test before new food beds settles any site-specific question.
How do gardeners stretch the season in Antonito?
With about 138 frost-free days between hard freezes, Antonito 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 166 to 194 days — and cold frames or low tunnels buy more. Starting transplants indoors ahead of the May 16 hard-freeze normal stretches the season without touching the calendar.
Everything above is measured at Antonito's scale — its 5a band and its 138-day season. Your yard writes its own version of Antonito'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 Antonito’s own scale
6 of the readings below were taken at Antonito's own scale — its own ~138-day season between 28°F freezes, the 273 acres it covers and 35 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Antonito's own USDA hardiness band, zones 5aUSDA PHZM 2023
- Antonito's own 28°F hard-freeze dates, about May 16 and Oct 1 and the ~138-day span between themNOAA 1991–2020 Climate Normals
- 35 documented contamination sites on the federal record near Antonito, the closest Underground Storage Tanks record about 0.2 miles out from the town centreFederal environmental registers
- Antonito's boundary and the 273 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5a and a ~138-day seasonGrowable Ground crop-matching engine
- The ecoregion at Antonito's own centroid, the Arizona/New Mexico PlateauUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Antonito's 273 acres read through its county's SSURGO summaryfrom Conejos County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Conejos 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 Conejos County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Antonito's 273 acreswhy one lot differs from the next →
- Which side of Antonito you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 273 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.2 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 Antonito-wide figureread your own land →
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