Green Valley, California, sits in USDA hardiness zone 9b — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
Reliable performers under these conditions include okra, meyer lemon, california poppy, and artichoke; what your own ground favors still comes down to its soil, sun, and drainage.
Even in Green 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 Green 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 Green Valley — soil, climate, flood, and parcel records. How we handle your address.
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Green Valley — the short answer
Green Valley, California: USDA zone 9b, about 335 days between hard freezes, across 5K acres of town.
- USDA zone
- 9b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Jan 15
- Solano County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Dec 16
- Solano County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~335
- Solano County normal — NOAA 1991–2020, nearest to this town
- Town area
- 5K 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 Solano County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 9b is Green Valley's average, not your lot's — a low corner or a tree line moves it. Against Green Valley's 335-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Green Valley
Each reading below is measured for Green Valley itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsGreen Valley runs about 335 days between hard freezes (read from Solano County, the closest normal to Green Valley) — 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
MeasuredGreen Valley sits in USDA hardiness zone 9b.
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 Green Valley is in
Green Valley sits in the Central California Foothills and Coastal Mountains — EPA Level III, inside the wider Mediterranean California. That is read at Green Valley's own centroid, and it is not what its county reads: Solano County is mostly Central California Valley. The wider page above you is answering a different question about different ground.
What Grows in Green Valley
Every plant below cleared Green Valley's own zone 9b and its 335-day season. Each card opens that plant's California profile. How we score.
Is it too late to plant in Green Valley?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Jan 1; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Jan 15 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 16 — long-season crops need about 90 days of runway, quick greens only 30. With almost year-round growing weather, timing is about heat and rainfall more than frost — some bench is always in play.
What's on the federal record near Green Valley
Closest first, within ~10 miles of Green Valley. Listing isn't leaking, and distance isn't exposure.
- BRUCE & PATTY TESTERBrownfields · 0.5 mi
- GREEN VALLEY COUNTRY CLUBBrownfields · 0.5 mi
- GRIFFIN SOIL GROUPBrownfields · 0.6 mi
- SOLANO IRRIGATION DISTRICTBrownfields · 0.6 mi
- B & L PROPERTIESBrownfields · 2.1 mi
- LANZA VINEYARDS INC/DBA WOODEN VALLEY WINERYBrownfields · 2.2 mi
- ANSELMO SERVICESBrownfields · 2.6 mi
- H&S Energy Products,#3048Underground Storage Tanks · 2.6 mi
- MR BIG SHOT TRUCKING SVCS INCBrownfields · 2.7 mi
- SOLANO COMMUNITY COLLEGEBrownfields · 2.8 mi
- CITY OF FAIRFIELDPFAS · 2.8 mi
- CAYMUS SUISUN WINERYBrownfields · 3.0 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Green 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 Green Valley.
Total Sites
1,257
within ~10 miles of Green Valley
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of Green Valley
Severity Distribution
within ~10 miles of Green Valley
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Green Valley, Brownfields runs higher than the national average — 1,082 sites within ~10 miles of Green Valley. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Brownfields: Brownfield sites are former commercial or industrial properties where legacy soil contamination (heavy metals, PAHs, petroleum compounds) may persist.
Check EPA brownfield remediation status — many sites have completed cleanup with institutional controls.
Check your specific parcel in Green 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 Green Valley average
Your land is one point inside Green Valley
Everything above resolves to Green Valley as a whole — one PHZM band, read across 5K acres, with hard-freeze dates borrowed from Solano County’s record because no 30-year normal resolves at this town’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 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 Green Valley Average
Green Valley Average
- ●USDA Zones 9b, averaged across Green Valley
- ●One soil character for all of Green Valley
- ●Frost dates read at Green Valley's scale: Jan 15 to Dec 16
YOUR Parcel
- ✓Your exact zone, not Green Valley's 9b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Green Valley
Pull a site-specific report for your exact address in Green Valley, California — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Green Valley averages can't show:
We read public map data around Green Valley — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Green Valley average
How we know this about Green Valley
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 Solano 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 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 Green Valley
When does frost risk typically end in Green Valley?
The last hard freeze (28°F) in Green Valley typically lands around Jan 15, 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 Feb 5.
When is the first frost in Green Valley?
The first hard freeze (28°F) in Green Valley typically arrives around Dec 16, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Dec 2, so the watching starts about Nov 16 — about 335 days after the spring freeze cleared.
How long is the growing season in Green Valley?
Measured between 28°F hard freezes, Green Valley sees about 335 frost-free days — roughly Jan 15 through Dec 16, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Feb 5 to Dec 2, about 300 days.
Is the soil safe to grow vegetables in Green Valley?
The federal record around Green Valley is a meaningful one — 1,257 documented sites, mostly Brownfields entries (1,082), the nearest Brownfields record about 0.5 miles out — so a soil test before new food beds is a sensible precaution here, not a reason to hold back from growing. Remember that proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what sits where.
How do I protect my plants from frost in Green Valley?
From about Nov 16 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 Dec 16 (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 Dec 16. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Green Valley's scale — its 9b band and its 335-day season. Your yard writes its own version of Green 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 Green Valley’s own scale
5 of the readings below were taken at Green Valley's own scale — the 5,357 acres it covers and 1,257 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- Green Valley's own USDA hardiness band, zones 9bUSDA PHZM 2023
- 1,257 documented contamination sites on the federal record near Green Valley, the closest Brownfields record about 0.5 miles out from the town centreFederal environmental registers
- Green Valley's boundary and the 5,357 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 9b and a ~335-day seasonGrowable Ground crop-matching engine
- Green Valley sits in the Central California Foothills and Coastal Mountains — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
Inherited from a wider read
- The 28°F hard-freeze dates — Green Valley has no normal of its own, so its county's is the closest measured readfrom Solano County
- Soil character — no town-scale survey exists, so Green Valley's 5,357 acres read through its county's SSURGO summaryfrom Solano County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Solano County
- The growing challenges every California grower plans around — written at state scale, so they stay on the state guidefrom California
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Solano County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Green Valley's 5,357 acreswhy one lot differs from the next →
- Which side of Green 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 5,357 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields 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 Green Valley-wide figureread your own land →
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