Sea Ranch, California, sits in USDA hardiness zone 10a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
The conditions favor avocado, meyer lemon, tomato, and artichoke, among others — though every individual site edits that list with its own soil, sun, and drainage.
Even in Sea Ranch, 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 Sea Ranch 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 Sea Ranch — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Sea Ranch — the short answer
Sea Ranch, California: USDA zone 10a, about 323 days between hard freezes, across 10K acres of town.
- USDA zone
- 10a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Jan 23
- Sonoma County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Dec 12
- Sonoma County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~323
- Sonoma County normal — NOAA 1991–2020, nearest to this town
- Town area
- 10K 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 Sonoma County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 10a is Sea Ranch's average, not your lot's — a low corner or a tree line moves it. Against Sea Ranch's 323-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Sea Ranch
Each reading below is measured for Sea Ranch itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsSea Ranch runs about 323 days between hard freezes (read from Sonoma County, the closest normal to Sea Ranch) — 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
MeasuredSea Ranch sits in USDA hardiness zone 10a.
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 Sea Ranch is in
Sea Ranch sits in the Coast Range — EPA Level III, inside the wider Marine West Coast Forest. That is read at Sea Ranch's own centroid, and it is not what its county reads: Sonoma County is mostly Central California Foothills and Coastal Mountains. The wider page above you is answering a different question about different ground.
What Grows in Sea Ranch
Plants matched to Sea Ranch's USDA zones 10a, ordered by how much hardiness margin each has here — the ones with room to spare at both ends of this town's band lead. Each links to its full growing profile.
Is it too late to plant in Sea Ranch?
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 23 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 12 — 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 Sea Ranch
Closest first, within ~10 miles of Sea Ranch. Listing isn't leaking, and distance isn't exposure.
- SEA RANCH WATER COMPANY,THE (PUC)PFAS · 0 ft
- MENDOCINO SOLID WASTE MANAGEMENT AUTHORITYBrownfields · 0.9 mi
- THE SEA RANCH ASSOCIATIONBrownfields · 2.3 mi
- THE SEA RANCH GOLF LINKSBrownfields · 3.7 mi
- Pepperwood CreekMining · 4.0 mi
- UnknownMining · 4.5 mi
- PACIFIC BELL C/O ALLEN TD043Brownfields · 4.7 mi
- SURF SUPER MARKET INC.Brownfields · 4.8 mi
- Gualala Unocal 76Underground Storage Tanks · 4.8 mi
- GUALALA UNION 76Brownfields · 4.8 mi
- Gualala ChevronUnderground Storage Tanks · 4.8 mi
- ANNAPOLIS TRANSFER STATIONBrownfields · 5.0 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Sea Ranch'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 Sea Ranch.
Total Sites
21
within ~10 miles of Sea Ranch
Risk Level
Moderate
Highest-severity
3 mining sites (prospects, none worked)
Sources Checked
within ~10 miles of Sea Ranch
Severity Distribution
within ~10 miles of Sea Ranch
Highest-Severity Sites
Know Before You Grow
- •Near a brownfield, raised beds of imported soil give your food clean ground.
- •Mine waste leaches heavy metals. Test for lead, arsenic and cadmium before growing food here.
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
Check your specific parcel in Sea Ranch
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 Sea Ranch average
Your land is one point inside Sea Ranch
Everything above resolves to Sea Ranch as a whole — one PHZM band, read across 10K acres, with hard-freeze dates borrowed from Sonoma 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 Sea Ranch Average
Sea Ranch Average
- ●USDA Zones 10a, averaged across Sea Ranch
- ●One soil character for all of Sea Ranch
- ●Frost dates read at Sea Ranch's scale: Jan 23 to Dec 12
YOUR Parcel
- ✓Your exact zone, not Sea Ranch's 10a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Sea Ranch
Pull a site-specific report for your exact address in Sea Ranch, California — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Sea Ranch averages can't show:
We read public map data around Sea Ranch — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Sea Ranch average
How we know this about Sea Ranch
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 Sonoma 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 Sea Ranch
When does frost risk typically end in Sea Ranch?
The last hard freeze (28°F) in Sea Ranch typically lands around Jan 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 Feb 13.
When is the first frost in Sea Ranch?
The first hard freeze (28°F) in Sea Ranch typically arrives around Dec 12, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 28, so the watching starts about Nov 12 — about 323 days after the spring freeze cleared.
How long is the growing season in Sea Ranch?
Measured between 28°F hard freezes, Sea Ranch sees about 323 frost-free days — roughly Jan 23 through Dec 12, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Feb 13 to Nov 28, about 288 days.
Is the soil safe to grow vegetables in Sea Ranch?
The federal record around Sea Ranch shows 21 documented sites, mostly Brownfields entries (14), the nearest PFAS 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 Sea Ranch?
From about Nov 12 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 12 (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 12. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Sea Ranch's scale — its 10a band and its 323-day season. Your yard writes its own version of Sea Ranch'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 Sea Ranch’s own scale
4 of the readings below were taken at Sea Ranch's own scale — the 10,315 acres it covers and 21 documented sites around it; 6 are borrowed from a wider read, named and linked below.
Measured here
- Sea Ranch's own USDA hardiness band, zones 10aUSDA PHZM 2023
- 21 documented contamination sites on the federal record near Sea Ranch, the closest PFAS record under a tenth of a mile out from the town centreFederal environmental registers
- Sea Ranch's boundary and the 10,315 acres inside itUS Census TIGER/Line 2025
- Sea Ranch sits in the Coast Range — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
Inherited from a wider read
- The 28°F hard-freeze dates — Sea Ranch has no normal of its own, so its county's is the closest measured readfrom Sonoma County
- Soil character — no town-scale survey exists, so Sea Ranch's 10,315 acres read through its county's SSURGO summaryfrom Sonoma County
- The candidate plant list — California's curated set, filtered to this zone band and re-ordered by how much margin each has herefrom California
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Sonoma 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 Sonoma County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Sea Ranch's 10,315 acreswhy one lot differs from the next →
- Which side of Sea Ranch you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 10,315 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest PFAS 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 Sea Ranch-wide figureread your own land →
More in California
Growing region
Nearby growing guides