Grass Valley, Oregon, sits in USDA hardiness zone 7a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
These conditions suit cabbage, hazelnut, california poppy, and collard greens — a starting list any specific site will trim or extend with its own soil, sun, and drainage.
Even in Grass Valley, 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 Grass Valley 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 Grass Valley — soil, climate, flood, and parcel records. How we handle your address.
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Grass Valley — the short answer
Grass Valley, Oregon: USDA zone 7a, about 224 days between hard freezes, across 327 acres of city.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 30
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 9
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~224
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 327 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 7a is Grass Valley's average, not your lot's — a low corner or a tree line moves it. Against Grass Valley's 224-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Grass Valley
Each reading below is measured for Grass Valley itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredGrass Valley runs about 224 days between hard freezes — 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
MeasuredGrass Valley sits in USDA hardiness zone 7a.
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 Grass Valley is in
Grass Valley sits in the Columbia Plateau — EPA Level III, inside the wider North American Deserts. That is read at Grass Valley's own centroid rather than borrowed from Sherman County.
What Grows in Grass Valley
Every plant below cleared Grass Valley's own zone 7a and its 224-day season. Each card opens that plant's Oregon profile. How we score.
Is it too late to plant in Grass Valley?
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 2; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 30 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 9 — long-season crops need about 90 days of runway, quick greens only 30. There is slack in a calendar like this — late plantings, second rounds of favorites, and a fall bench that keeps beds working.
Documented around Grass Valley
Survey cells within 31 miles of Grass Valley checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 531 miles off. What to watch for.
What's on the federal record near Grass Valley
Closest first, within ~10 miles of Grass Valley. Listing isn't leaking, and distance isn't exposure.
- ROADHOUSE 97Underground Storage Tanks · 400 ft
- AT&T - GRASS VALLEY TD-2Underground Storage Tanks · 600 ft
- MID COLUMBIA PRODUCERS, INCUnderground Storage Tanks · 900 ft
- 02.00S/16.00E-34AAA3Nitrate · 1300 ft
- EVERGREEN STATE HOLDINGSBrownfields · 1500 ft
- WASCO ELEC COOP - GRASS VALLEY WAREHOUSEUnderground Storage Tanks · 7.7 mi
- AT&T - MORO TD-2 MOROORQ1770Underground Storage Tanks · 8.9 mi
- SHERMAN HIGH SCHOOLUnderground Storage Tanks · 8.9 mi
- BAR JJ RANCHUnderground Storage Tanks · 8.9 mi
- OLD BUS BARN SHERMAN COUNTY SCHOOL DISTUnderground Storage Tanks · 8.9 mi
- MID COLUMBIA PRODUCERS INCUnderground Storage Tanks · 8.9 mi
- MORO MEDICAL CLINICUnderground Storage Tanks · 8.9 mi
5 more sites are on the record inside the same radius. See them on the map
Measured from Grass Valley'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 Grass Valley.
Sources Checked
within ~10 miles of Grass Valley
Severity Distribution
within ~10 miles of Grass Valley
Highest-Severity Sites
Know Before You Grow
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
- •On a private well, test for nitrates: above 10 mg/L the water needs treatment before irrigating.
- •Near a brownfield, raised beds of imported soil give your food clean ground.
Check your specific parcel in Grass Valley
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 Grass Valley average
Your land is one point inside Grass Valley
Everything above resolves to Grass Valley as a whole — one PHZM band and one 28°F frost record, read across 327 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 Grass Valley Average
Grass Valley Average
- ●USDA Zones 7a, averaged across Grass Valley
- ●One soil character for all of Grass Valley
- ●Frost dates read at Grass Valley's scale: Mar 30 to Nov 9
YOUR Parcel
- ✓Your exact zone, not Grass Valley's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Grass Valley
Pull a site-specific report for your exact address in Grass Valley, Oregon — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Grass Valley averages can't show:
We read public map data around Grass Valley — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Grass Valley average
How we know this about Grass Valley
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 Grass Valley’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 Grass Valley
When does frost risk typically end in Grass Valley?
The last hard freeze (28°F) in Grass Valley typically lands around Mar 30, 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 20.
When is the first frost in Grass Valley?
The first hard freeze (28°F) in Grass Valley typically arrives around Nov 9, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 26, so the watching starts about Oct 10 — about 224 days after the spring freeze cleared.
How long is the growing season in Grass Valley?
Measured between 28°F hard freezes, Grass Valley sees about 224 frost-free days — roughly Mar 30 through Nov 9, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 20 to Oct 26, about 189 days.
Is the soil safe to grow vegetables in Grass Valley?
The federal record around Grass Valley is light — 19 documented sites across the 9 federal source types we checked, mostly Underground Storage Tanks entries (16), the nearest Underground Storage Tanks record under a tenth of a mile out — and proximity to a documented site is information, not a diagnosis of any one yard. Growing food here starts from a strong position; a soil test before new food beds settles any site-specific question.
How do I protect my plants from frost in Grass Valley?
From about Oct 10 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 9 (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 9. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Grass Valley's scale — its 7a band and its 224-day season. Your yard writes its own version of Grass Valley'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 Grass Valley’s own scale
7 of the readings below were taken at Grass Valley's own scale — its own ~224-day season between 28°F freezes, the 327 acres it covers and 19 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Grass Valley's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Grass Valley's own 28°F hard-freeze dates, about Mar 30 and Nov 9 and the ~224-day span between themNOAA 1991–2020 Climate Normals
- 19 documented contamination sites on the federal record near Grass Valley, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Grass Valley's boundary and the 327 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~224-day seasonGrowable Ground crop-matching engine
- The ecoregion at Grass Valley's own centroid, the Columbia PlateauUS EPA Level III Ecoregions
- Lanternfly survey cells around Grass Valley checked, none carrying a detectionlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Grass Valley's 327 acres read through its county's SSURGO summaryfrom Sherman County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Sherman 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 Sherman County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Grass Valley's 327 acreswhy one lot differs from the next →
- Which side of Grass Valley you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 327 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 Grass Valley-wide figureread your own land →
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