Sierra Ridge, Colorado, sits in USDA hardiness zone 6a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
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 Sierra Ridge, 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 Sierra Ridge 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 Sierra Ridge — soil, climate, flood, and parcel records. How we handle your address.
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Sierra Ridge — the short answer
Sierra Ridge, Colorado: USDA zone 6a, about 170 days between hard freezes, across 324 acres of town.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 28
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 15
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~170
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 324 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 Sierra Ridge's average, not your lot's — a low corner or a tree line moves it. Against Sierra Ridge's 170-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Sierra Ridge
Each reading below is measured for Sierra Ridge itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredSierra Ridge runs about 170 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
MeasuredSierra Ridge 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 Sierra Ridge is in
Sierra Ridge sits in the High Plains — EPA Level III, inside the wider Great Plains. That is read at Sierra Ridge'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 Sierra Ridge
Every plant below cleared Sierra Ridge's own zone 6a and its 170-day season. Each card opens that plant's Colorado profile. How we score.
Is it too late to plant in Sierra Ridge?
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 Mar 31; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 28 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 15 — long-season crops need about 90 days of runway, quick greens only 30. Late in the year the fall bench takes over — quick greens, radishes, and garlic that repays you next summer.
What's on the federal record near Sierra Ridge
Closest first, within ~10 miles of Sierra Ridge. Listing isn't leaking, and distance isn't exposure.
- SC0066617BCD SWQA-12Nitrate · 2600 ft
- SC00606607DBD DAWMAS07Nitrate · 0.8 mi
- SC00606607CAC DENMAS08Nitrate · 0.9 mi
- SC00606609AABNitrate · 1.0 mi
- SC00606608CBBNitrate · 1.1 mi
- Circle K Store #2709893Underground Storage Tanks · 1.1 mi
- Twin Star Energy #515Underground Storage Tanks · 1.3 mi
- SC00606617DDDNitrate · 1.3 mi
- CVS PHARMACY #10785Brownfields · 1.3 mi
- CVS 10785 CO LLCUnderground Storage Tanks · 1.3 mi
- 7-Eleven #32923Underground Storage Tanks · 1.4 mi
- Parker Fire Protection DistrictUnderground Storage Tanks · 1.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Sierra Ridge'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 Sierra Ridge.
Sources Checked
within ~10 miles of Sierra Ridge
Severity Distribution
within ~10 miles of Sierra Ridge
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Sierra Ridge, PFAS runs higher than the national average — 12 sites within ~10 miles of Sierra Ridge. 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.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Check your specific parcel in Sierra Ridge
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 Sierra Ridge average
Your land is one point inside Sierra Ridge
Everything above resolves to Sierra Ridge as a whole — one PHZM band and one 28°F frost record, read across 324 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 Sierra Ridge Average
Sierra Ridge Average
- ●USDA Zones 6a, averaged across Sierra Ridge
- ●One soil character for all of Sierra Ridge
- ●Frost dates read at Sierra Ridge's scale: Apr 28 to Oct 15
YOUR Parcel
- ✓Your exact zone, not Sierra Ridge's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Sierra Ridge
Pull a site-specific report for your exact address in Sierra Ridge, Colorado — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Sierra Ridge averages can't show:
We read public map data around Sierra Ridge — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Sierra Ridge average
How we know this about Sierra Ridge
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 Sierra Ridge’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 Sierra Ridge
When does frost risk typically end in Sierra Ridge?
The last hard freeze (28°F) in Sierra Ridge typically lands around Apr 28, 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 19.
When is the first frost in Sierra Ridge?
The first hard freeze (28°F) in Sierra Ridge typically arrives around Oct 15, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 1, so the watching starts about Sep 15 — about 170 days after the spring freeze cleared.
How long is the growing season in Sierra Ridge?
Measured between 28°F hard freezes, Sierra Ridge sees about 170 frost-free days — roughly Apr 28 through Oct 15, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 19 to Oct 1, about 135 days.
Is the soil safe to grow vegetables in Sierra Ridge?
The federal record around Sierra Ridge runs heavier than most — 1,136 documented sites, mostly Underground Storage Tanks entries (441), the nearest Nitrate record about 0.5 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 Sierra Ridge?
From about Sep 15 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 15 (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 15. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Sierra Ridge's scale — its 6a band and its 170-day season. Your yard writes its own version of Sierra Ridge'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 Sierra Ridge’s own scale
6 of the readings below were taken at Sierra Ridge's own scale — its own ~170-day season between 28°F freezes, the 324 acres it covers and 1,136 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Sierra Ridge's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Sierra Ridge's own 28°F hard-freeze dates, about Apr 28 and Oct 15 and the ~170-day span between themNOAA 1991–2020 Climate Normals
- 1,136 documented contamination sites on the federal record near Sierra Ridge, the closest Nitrate record about 0.5 miles out from the town centreFederal environmental registers
- Sierra Ridge's boundary and the 324 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~170-day seasonGrowable Ground crop-matching engine
- Sierra Ridge 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 Sierra Ridge's 324 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 Sierra Ridge's 324 acreswhy one lot differs from the next →
- Which side of Sierra Ridge you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 324 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate 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 Sierra Ridge-wide figureread your own land →
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