Stepping Stone, Colorado, sits in USDA hardiness zone 6a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
On paper, cabbage, blackberry, california poppy, and collard greens all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Even in Stepping Stone, 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 Stepping Stone 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 Stepping Stone — soil, climate, flood, and parcel records. How we handle your address.
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Stepping Stone — the short answer
Stepping Stone, Colorado: USDA zone 6a, about 166 days between hard freezes, across 470 acres of town.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 1
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 14
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~166
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 470 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 Stepping Stone's average, not your lot's — a low corner or a tree line moves it. Against Stepping Stone's 166-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Stepping Stone
Each reading below is measured for Stepping Stone itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredStepping Stone runs about 166 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
MeasuredStepping Stone 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 Stepping Stone is in
Stepping Stone sits in the High Plains — EPA Level III, inside the wider Great Plains. That is read at Stepping Stone's own centroid, and it is not what its county reads: Douglas County is mostly Southwestern Tablelands. The wider page above you is answering a different question about different ground.
What Grows in Stepping Stone
Every plant below cleared Stepping Stone's own zone 6a and its 166-day season. Each card opens that plant's Colorado profile. How we score.
Is it too late to plant in Stepping Stone?
Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. Cool-season crops can go in from around Apr 3; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 1 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 14 — 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 Stepping Stone
Closest first, within ~10 miles of Stepping Stone. Listing isn't leaking, and distance isn't exposure.
- SC0066617BCD SWQA-12Nitrate · 1.3 mi
- SC0066629BDD SWQA-7Nitrate · 1.3 mi
- SC00606617DDDNitrate · 1.6 mi
- T Square ConocoUnderground Storage Tanks · 1.7 mi
- SC00606607CAC DENMAS08Nitrate · 1.8 mi
- SC00606607DBD DAWMAS07Nitrate · 1.8 mi
- Circle K Store #2709893Underground Storage Tanks · 1.8 mi
- Parker Fire Protection DistrictUnderground Storage Tanks · 1.9 mi
- THE CENTER AT LINCOLNBrownfields · 2.0 mi
- SC00606616CBD URLUS 13Nitrate · 2.0 mi
- Twin Star Energy #515Underground Storage Tanks · 2.0 mi
- SC00606609AABNitrate · 2.0 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Stepping Stone'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 Stepping Stone.
Total Sites
1,078
within ~10 miles of Stepping Stone
Risk Level
High
Highest-severity
3 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Stepping Stone
Severity Distribution
within ~10 miles of Stepping Stone
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Stepping Stone, PFAS runs higher than the national average — 11 sites within ~10 miles of Stepping Stone. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Check your specific parcel in Stepping Stone
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 Stepping Stone average
Your land is one point inside Stepping Stone
Everything above resolves to Stepping Stone as a whole — one PHZM band and one 28°F frost record, read across 470 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 Stepping Stone Average
Stepping Stone Average
- ●USDA Zones 6a, averaged across Stepping Stone
- ●One soil character for all of Stepping Stone
- ●Frost dates read at Stepping Stone's scale: May 1 to Oct 14
YOUR Parcel
- ✓Your exact zone, not Stepping Stone's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Stepping Stone
Pull a site-specific report for your exact address in Stepping Stone, Colorado — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Stepping Stone averages can't show:
We read public map data around Stepping Stone — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Stepping Stone average
How we know this about Stepping Stone
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 Stepping Stone’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 Stepping Stone
When does frost risk typically end in Stepping Stone?
The last hard freeze (28°F) in Stepping Stone typically lands around May 1, 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 22.
When is the first frost in Stepping Stone?
The first hard freeze (28°F) in Stepping Stone typically arrives around Oct 14, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Sep 30, so the watching starts about Sep 14 — about 166 days after the spring freeze cleared.
How long is the growing season in Stepping Stone?
Measured between 28°F hard freezes, Stepping Stone sees about 166 frost-free days — roughly May 1 through Oct 14, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 22 to Sep 30, about 131 days.
Is the soil safe to grow vegetables in Stepping Stone?
The federal record around Stepping Stone runs heavier than most — 1,078 documented sites, mostly Underground Storage Tanks entries (435), the nearest Nitrate record about 1.3 miles out — 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.
How do I protect my plants from frost in Stepping Stone?
From about Sep 14 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 14 (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 14. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Stepping Stone's scale — its 6a band and its 166-day season. Your yard writes its own version of Stepping Stone'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 Stepping Stone’s own scale
6 of the readings below were taken at Stepping Stone's own scale — its own ~166-day season between 28°F freezes, the 470 acres it covers and 1,078 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Stepping Stone's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Stepping Stone's own 28°F hard-freeze dates, about May 1 and Oct 14 and the ~166-day span between themNOAA 1991–2020 Climate Normals
- 1,078 documented contamination sites on the federal record near Stepping Stone, the closest Nitrate record about 1.3 miles out from the town centreFederal environmental registers
- Stepping Stone's boundary and the 470 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~166-day seasonGrowable Ground crop-matching engine
- Stepping Stone sits in the High Plains — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Stepping Stone's 470 acres read through its county's SSURGO summaryfrom Douglas County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Douglas 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 Douglas County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Stepping Stone's 470 acreswhy one lot differs from the next →
- Which side of Stepping Stone you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 470 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate record about 1.3 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 Stepping Stone-wide figureread your own land →
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