Littleton, Colorado, sits in USDA hardiness zone 6a — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
Growers here do well with cabbage, hazelnut, lavender, and collard greens — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Even in Littleton, 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 Littleton 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 Littleton — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Littleton — the short answer
Littleton, Colorado: USDA zone 6a, about 181 days between hard freezes, across 8K acres of city.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 22
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 20
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~181
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 8K 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 Littleton's average, not your lot's — a low corner or a tree line moves it. Against Littleton's 181-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Littleton
Each reading below is measured for Littleton itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredLittleton runs about 181 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
MeasuredLittleton 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 Littleton is in
Littleton sits in the High Plains — EPA Level III, inside the wider Great Plains. That is read at Littleton's own centroid rather than borrowed from Arapahoe County.
What Grows in Littleton
Every plant below cleared Littleton's own zone 6a and its 181-day season. Each card opens that plant's Colorado profile. How we score.
Is it too late to plant in Littleton?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Mar 25; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 22 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 20 — 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 Littleton
Closest first, within ~10 miles of Littleton. Listing isn't leaking, and distance isn't exposure.
- BRECKENRIDGE BREWERYBrownfields · 900 ft
- LITTLETON DAY SURGERY CENTERBrownfields · 1400 ft
- SC00506828BCC USGS 393539105005401Nitrate · 1900 ft
- Littleton PlantUnderground Storage Tanks · 2000 ft
- PORTRAIT INNOVATIONSBrownfields · 0.5 mi
- ENGLEWOOD CITY OFPFAS · 0.5 mi
- Meadowood CorpUnderground Storage Tanks · 0.7 mi
- 7-Eleven #34486Underground Storage Tanks · 0.8 mi
- Santa Fe 66Underground Storage Tanks · 0.9 mi
- CONOCOPHILLIPS # 27614Brownfields · 1.0 mi
- Jazz Car Wash & DetailingUnderground Storage Tanks · 1.1 mi
- Columbine Country ClubUnderground Storage Tanks · 1.1 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Littleton'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 Littleton.
Sources Checked
within ~10 miles of Littleton
Severity Distribution
within ~10 miles of Littleton
Highest-Severity Sites
Know Before You Grow
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
- •Near a brownfield, raised beds of imported soil give your food clean ground.
- •On a private well, test for nitrates: above 10 mg/L the water needs treatment before irrigating.
Check your specific parcel in Littleton
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 Littleton average
Your land is one point inside Littleton
Everything above resolves to Littleton as a whole — one PHZM band and one 28°F frost record, read across 8K 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 Littleton Average
Littleton Average
- ●USDA Zones 6a, averaged across Littleton
- ●One soil character for all of Littleton
- ●Frost dates read at Littleton's scale: Apr 22 to Oct 20
YOUR Parcel
- ✓Your exact zone, not Littleton's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Littleton
Pull a site-specific report for your exact address in Littleton, Colorado — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Littleton averages can't show:
We read public map data around Littleton — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Littleton average
How we know this about Littleton
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 Littleton’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 Littleton
When does frost risk typically end in Littleton?
The last hard freeze (28°F) in Littleton typically lands around Apr 22, 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 13.
When is the first frost in Littleton?
The first hard freeze (28°F) in Littleton typically arrives around Oct 20, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 6, so the watching starts about Sep 20 — about 181 days after the spring freeze cleared.
How long is the growing season in Littleton?
Measured between 28°F hard freezes, Littleton sees about 181 frost-free days — roughly Apr 22 through Oct 20, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 13 to Oct 6, about 146 days.
Is the soil safe to grow vegetables in Littleton?
The federal record around Littleton is a meaningful one — 2,674 documented sites, mostly Underground Storage Tanks entries (1,507), the nearest Brownfields record about 0.2 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 Littleton?
From about Sep 20 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 20 (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 20. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Littleton's scale — its 6a band and its 181-day season. Your yard writes its own version of Littleton'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 Littleton’s own scale
6 of the readings below were taken at Littleton's own scale — its own ~181-day season between 28°F freezes, the 8,076 acres it covers and 2,674 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Littleton's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Littleton's own 28°F hard-freeze dates, about Apr 22 and Oct 20 and the ~181-day span between themNOAA 1991–2020 Climate Normals
- 2,674 documented contamination sites on the federal record near Littleton, the closest Brownfields record about 0.2 miles out from the town centreFederal environmental registers
- Littleton's boundary and the 8,076 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~181-day seasonGrowable Ground crop-matching engine
- The ecoregion at Littleton's own centroid, the High PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Littleton's 8,076 acres read through its county's SSURGO summaryfrom Arapahoe County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Arapahoe 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 Arapahoe County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Littleton's 8,076 acreswhy one lot differs from the next →
- Which side of Littleton you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 8,076 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields 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 Littleton-wide figureread your own land →