Silverton, Oregon, sits in USDA hardiness zone 8b — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
Well-matched crops include cabbage, fig, california poppy, and collard greens, and the gap between "grows in the area" and "grows in your yard" is closed by soil, sun, and drainage.
Even in Silverton, 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 Silverton 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 Silverton — soil, climate, flood, and parcel records. How we handle your address.
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Silverton — the short answer
Silverton, Oregon: USDA zone 8b, about 243 days between hard freezes, across 2K acres of city.
- USDA zone
- 8b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 23
- Marion County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Nov 21
- Marion County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~243
- Marion County normal — NOAA 1991–2020, nearest to this town
- City area
- 2K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. No 30-year normal resolves at this town’s own centroid, so the hard-freeze dates are Marion County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 8b is Silverton's average, not your lot's — a low corner or a tree line moves it. Against Silverton's 243-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Silverton
Each reading below is measured for Silverton itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsSilverton runs about 243 days between hard freezes (read from Marion County, the closest normal to Silverton) — a long growing season.
There is slack for succession plantings and slow-finishing crops: many vegetables can be sown twice, and the heat-lovers have time to ripen fully.
Plan a second sowing of quick crops after the first comes out, and use the fall window most gardeners let sit idle.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredSilverton 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 Silverton is in
Silverton sits in the Willamette Valley — EPA Level III, inside the wider Marine West Coast Forest. That is read at Silverton's own centroid rather than borrowed from Marion County.
What Grows in Silverton
Every plant below cleared Silverton's own zone 8b and its 243-day season. Each card opens that plant's Oregon profile. How we score.
Is it too late to plant in Silverton?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Feb 23; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 23 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 21 — long-season crops need about 90 days of runway, quick greens only 30. With a season this long, “too late” mostly means “switch crops” — second sowings and a full fall garden are the norm, with garlic closing the year.
Documented around Silverton
Survey cells within 31 miles of Silverton checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 502 miles off. What to watch for.
What's on the federal record near Silverton
Closest first, within ~10 miles of Silverton. Listing isn't leaking, and distance isn't exposure.
- GENO'S SHELLUnderground Storage Tanks · 600 ft
- SILVERTONUnderground Storage Tanks · 750 ft
- SILVERTON POST OFFICEUnderground Storage Tanks · 1200 ft
- HATTEBERGS CHEVRONUnderground Storage Tanks · 1300 ft
- ALLIED PHOTO INCUnderground Storage Tanks · 2000 ft
- DONAHUE, CONRADUnderground Storage Tanks · 2000 ft
- SILVERCREEK SHELLUnderground Storage Tanks · 2100 ft
- LEGACY SILVERTON MEDICAL CENTERBrownfields · 2500 ft
- SILVERTON HOSPITALUnderground Storage Tanks · 2600 ft
- GARDEN WAY CHEVRONUnderground Storage Tanks · 0.5 mi
- DAVID, VICTOR PUnderground Storage Tanks · 0.5 mi
- HOLLAND COLLISION SERVICEBrownfields · 0.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Silverton'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 Silverton.
Total Sites
187
within ~10 miles of Silverton
Risk Level
Moderate
Highest-severity
8 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Silverton
Severity Distribution
within ~10 miles of Silverton
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Silverton, two things run higher than the national average within ~10 miles of Silverton — PFAS (5 sites) and CAFO (3 sites). 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.
CAFO: CAFOs pose a different contamination profile than chemical sources.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.
Check your specific parcel in Silverton
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 Silverton average
Your land is one point inside Silverton
Everything above resolves to Silverton as a whole — one PHZM band, read across 2K acres, with hard-freeze dates borrowed from Marion County’s record because no 30-year normal resolves at this city’s own centroid. 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 Silverton Average
Silverton Average
- ●USDA Zones 8b, averaged across Silverton
- ●One soil character for all of Silverton
- ●Frost dates read at Silverton's scale: Mar 23 to Nov 21
YOUR Parcel
- ✓Your exact zone, not Silverton's 8b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Silverton
Pull a site-specific report for your exact address in Silverton, Oregon — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Silverton averages can't show:
We read public map data around Silverton — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Silverton average
How we know this about Silverton
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 Marion County’s record, because none resolves here; 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 Silverton
When does frost risk typically end in Silverton?
The last hard freeze (28°F) in Silverton typically lands around Mar 23, 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 Apr 13.
When is the first frost in Silverton?
The first hard freeze (28°F) in Silverton typically arrives around Nov 21, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 7, so the watching starts about Oct 22 — about 243 days after the spring freeze cleared.
How long is the growing season in Silverton?
Measured between 28°F hard freezes, Silverton sees about 243 frost-free days — roughly Mar 23 through Nov 21, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 13 to Nov 7, about 208 days.
Is the soil safe to grow vegetables in Silverton?
The federal record around Silverton shows 187 documented sites, mostly Underground Storage Tanks entries (135), the nearest Underground Storage Tanks record about 0.1 miles 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 Silverton?
From about Oct 22 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 21 (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 21. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Silverton's scale — its 8b band and its 243-day season. Your yard writes its own version of Silverton'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 Silverton’s own scale
6 of the readings below were taken at Silverton's own scale — the 2,244 acres it covers and 187 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- Silverton's own USDA hardiness band, zones 8bUSDA PHZM 2023
- 187 documented contamination sites on the federal record near Silverton, the closest Underground Storage Tanks record about 0.1 miles out from the town centreFederal environmental registers
- Silverton's boundary and the 2,244 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 8b and a ~243-day seasonGrowable Ground crop-matching engine
- The ecoregion at Silverton's own centroid, the Willamette ValleyUS EPA Level III Ecoregions
- Lanternfly survey cells around Silverton checked, none carrying a detectionlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- The 28°F hard-freeze dates — Silverton has no normal of its own, so its county's is the closest measured readfrom Marion County
- Soil character — no town-scale survey exists, so Silverton's 2,244 acres read through its county's SSURGO summaryfrom Marion County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Marion 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 Marion County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Silverton's 2,244 acreswhy one lot differs from the next →
- Which side of Silverton you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 2,244 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.1 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 Silverton-wide figureread your own land →