Mill City, Oregon, sits in USDA hardiness zone 8b — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Among the crops suited to this profile: cabbage, fig, california poppy, and collard greens. The site-level story — soil, sun, drainage — decides the rest.
Even in Mill City, 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 Mill City 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 Mill City — soil, climate, flood, and parcel records. How we handle your address.
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Mill City — the short answer
Mill City, Oregon: USDA zone 8b, about 276 days between hard freezes, across 577 acres of city.
- USDA zone
- 8b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Feb 22
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 25
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~276
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 577 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 8b is Mill City's average, not your lot's — a low corner or a tree line moves it. Against Mill City's 276-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Mill City
Each reading below is measured for Mill City itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredMill City runs about 276 days between hard freezes — close to year-round growing.
Frost is rarely the limit here; winter plantings are as real as summer ones, and the harder question is which crops shrug off the summer heat.
Grow cool-season crops through the mild winter, and choose heat-tolerant varieties for the summer beds.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredMill City sits in USDA hardiness zone 8b.
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 Mill City is in
Mill City sits in the Willamette Valley — EPA Level III, inside the wider Marine West Coast Forest. That is read at Mill City's own centroid, and it is not what its county reads: Linn County is mostly Cascades. The wider page above you is answering a different question about different ground.
What Grows in Mill City
Every plant below cleared Mill City's own zone 8b and its 276-day season. Each card opens that plant's Oregon profile. How we score.
Is it too late to plant in Mill City?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Jan 25; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Feb 22 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 25 — long-season crops need about 90 days of runway, quick greens only 30. Here the calendar nearly circles: cool-season crops take the winter shift, and the next window is always close.
What's on the federal record near Mill City
Closest first, within ~10 miles of Mill City. Listing isn't leaking, and distance isn't exposure.
- MILL CITY CENTRAL OFFICEUnderground Storage Tanks · 450 ft
- MILL CITY, CITY OFUnderground Storage Tanks · 650 ft
- MILL CITY SHELL STATIONUnderground Storage Tanks · 700 ft
- DETROIT DAM PROJECTUnderground Storage Tanks · 1500 ft
- JONES FAMILY REVOCABLE TRUSTUnderground Storage Tanks · 2200 ft
- OREGON DEPARTMENT OF TRANSPORTATION DETROIT MAINTENANCE FACILITYBrownfields · 2500 ft
- MILL CITY MOBILUnderground Storage Tanks · 2600 ft
- MILL CITY TEXACOUnderground Storage Tanks · 1.2 mi
- FRED A MOORE INCUnderground Storage Tanks · 1.3 mi
- FRANK LUMBER CO INCUnderground Storage Tanks · 1.3 mi
- PHILLIPS 66 SITE - ABANDONEDUnderground Storage Tanks · 2.5 mi
- AT&TUnderground Storage Tanks · 2.9 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Mill City'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 Mill City.
Severity Distribution
within ~10 miles of Mill City
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Mill City, two things run higher than the national average within ~10 miles of Mill City — Mining (7 sites) and Underground Storage Tanks (28 sites). That's not a problem with your land — it's information about it.
Mining: Mining sites — both historic and active — can leach heavy metals (arsenic, lead, cadmium, mercury) into soil and water for centuries after operations cease.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Test soil for heavy metals (lead, arsenic, cadmium, mercury) — this is essential near any mining site.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check your specific parcel in Mill City
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 Mill City average
Your land is one point inside Mill City
Everything above resolves to Mill City as a whole — one PHZM band and one 28°F frost record, read across 577 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 Mill City Average
Mill City Average
- ●USDA Zones 8b, averaged across Mill City
- ●One soil character for all of Mill City
- ●Frost dates read at Mill City's scale: Feb 22 to Nov 25
YOUR Parcel
- ✓Your exact zone, not Mill City's 8b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Mill City
Pull a site-specific report for your exact address in Mill City, Oregon — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Mill City averages can't show:
We read public map data around Mill City — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Mill City average
How we know this about Mill City
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 Mill City’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 Mill City
When does frost risk typically end in Mill City?
The last hard freeze (28°F) in Mill City typically lands around Feb 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 Mar 15.
When is the first frost in Mill City?
The first hard freeze (28°F) in Mill City typically arrives around Nov 25, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 11, so the watching starts about Oct 26 — about 276 days after the spring freeze cleared.
How long is the growing season in Mill City?
Measured between 28°F hard freezes, Mill City sees about 276 frost-free days — roughly Feb 22 through Nov 25, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Mar 15 to Nov 11, about 241 days.
Is the soil safe to grow vegetables in Mill City?
The federal record around Mill City shows 41 documented sites, mostly Underground Storage Tanks entries (28), the nearest Underground Storage Tanks record under a tenth of a mile out — a typical footprint for a growing area, and proximity to a documented site is information, not a diagnosis of any one yard. It's worth seeing which recorded sites sit closest to where you grow, and testing the soil before new food beds near any of them.
How do I protect my plants from frost in Mill City?
From about Oct 26 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 Nov 25 (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 Nov 25. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Mill City's scale — its 8b band and its 276-day season. Your yard writes its own version of Mill City'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 Mill City’s own scale
6 of the readings below were taken at Mill City's own scale — its own ~276-day season between 28°F freezes, the 577 acres it covers and 41 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Mill City's own USDA hardiness band, zones 8bUSDA PHZM 2023
- Mill City's own 28°F hard-freeze dates, about Feb 22 and Nov 25 and the ~276-day span between themNOAA 1991–2020 Climate Normals
- 41 documented contamination sites on the federal record near Mill City, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Mill City's boundary and the 577 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 8b and a ~276-day seasonGrowable Ground crop-matching engine
- Mill City sits in the Willamette Valley — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Mill City's 577 acres read through its county's SSURGO summaryfrom Linn County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Linn County
- The growing challenges every Oregon grower plans around — written at state scale, so they stay on the state guidefrom Oregon
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Linn County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Mill City's 577 acreswhy one lot differs from the next →
- Which side of Mill City you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 577 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 Mill City-wide figureread your own land →