Glendale, Colorado, sits in USDA hardiness zone 6a — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Crops well matched to these conditions include cabbage, hazelnut, lavender, and collard greens — though what thrives on any one site still turns on its specific soil, sun, and drainage.
Even in Glendale, 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 Glendale 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 Glendale — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Glendale — the short answer
Glendale, Colorado: USDA zone 6a, about 182 days between hard freezes, across 364 acres of city.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 20
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 19
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~182
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 364 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 Glendale's average, not your lot's — a low corner or a tree line moves it. Against Glendale's 182-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Glendale
Each reading below is measured for Glendale itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredGlendale runs about 182 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
MeasuredGlendale 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 Glendale is in
Glendale sits in the High Plains — EPA Level III, inside the wider Great Plains. That is read at Glendale's own centroid rather than borrowed from Arapahoe County.
What Grows in Glendale
Every plant below cleared Glendale's own zone 6a and its 182-day season. Each card opens that plant's Colorado profile. How we score.
Is it too late to plant in Glendale?
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 23; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 20 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 19 — long-season crops need about 90 days of runway, quick greens only 30. As the window narrows, the plantings just get faster — fall brassicas, then greens, then garlic to finish.
What's on the federal record near Glendale
Closest first, within ~10 miles of Glendale. Listing isn't leaking, and distance isn't exposure.
- Cherry Creek Corporate CenterUnderground Storage Tanks · 150 ft
- Campus At Cherry CreekUnderground Storage Tanks · 750 ft
- CDPHE MERCURYSuperfund · 1000 ft
- MONY REAL ESTATEBrownfields · 1100 ft
- Bull And BushUnderground Storage Tanks · 1100 ft
- Galleria Towers IncUnderground Storage Tanks · 1100 ft
- UnknownUnderground Storage Tanks · 1100 ft
- CHERRY CREEK AT GLENDALE, CO - PWNitrate · 1100 ft
- Plaza Ii LtdUnderground Storage Tanks · 1200 ft
- PORE WATER AT 06713300Nitrate · 1200 ft
- KING SOOPERS 21Brownfields · 1300 ft
- FIRESTONE TIRE SERVICE CENTERBrownfields · 1400 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Glendale'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 Glendale.
Sources Checked
within ~10 miles of Glendale
Severity Distribution
within ~10 miles of Glendale
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 Glendale
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 Glendale average
Your land is one point inside Glendale
Everything above resolves to Glendale as a whole — one PHZM band and one 28°F frost record, read across 364 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 Glendale Average
Glendale Average
- ●USDA Zones 6a, averaged across Glendale
- ●One soil character for all of Glendale
- ●Frost dates read at Glendale's scale: Apr 20 to Oct 19
YOUR Parcel
- ✓Your exact zone, not Glendale's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Glendale
Pull a site-specific report for your exact address in Glendale, Colorado — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Glendale averages can't show:
We read public map data around Glendale — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Glendale average
How we know this about Glendale
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 Glendale’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 Glendale
When does frost risk typically end in Glendale?
The last hard freeze (28°F) in Glendale typically lands around Apr 20, 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 11.
When is the first frost in Glendale?
The first hard freeze (28°F) in Glendale typically arrives around Oct 19, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 5, so the watching starts about Sep 19 — about 182 days after the spring freeze cleared.
How long is the growing season in Glendale?
Measured between 28°F hard freezes, Glendale sees about 182 frost-free days — roughly Apr 20 through Oct 19, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 11 to Oct 5, about 147 days.
Is the soil safe to grow vegetables in Glendale?
The federal record around Glendale runs heavier than most — 5,657 documented sites, mostly Underground Storage Tanks entries (3,222), the nearest Underground Storage Tanks record under a tenth of a mile 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 Glendale?
From about Sep 19 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 19 (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 19. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Glendale's scale — its 6a band and its 182-day season. Your yard writes its own version of Glendale'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 Glendale’s own scale
6 of the readings below were taken at Glendale's own scale — its own ~182-day season between 28°F freezes, the 364 acres it covers and 5,657 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Glendale's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Glendale's own 28°F hard-freeze dates, about Apr 20 and Oct 19 and the ~182-day span between themNOAA 1991–2020 Climate Normals
- 5,657 documented contamination sites on the federal record near Glendale, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Glendale's boundary and the 364 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~182-day seasonGrowable Ground crop-matching engine
- The ecoregion at Glendale's own centroid, the High PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Glendale's 364 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 Glendale's 364 acreswhy one lot differs from the next →
- Which side of Glendale you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 364 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record under a tenth of a mile 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 Glendale-wide figureread your own land →