Westhaven-Moonstone, 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.
Expect okra, meyer lemon, california poppy, and artichoke to be strong candidates here; the deciding factors on any one parcel stay local — soil, sun, and drainage.
Even in Westhaven-Moonstone, 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 Westhaven-Moonstone 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 Westhaven-Moonstone — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Westhaven-Moonstone — the short answer
Westhaven-Moonstone, California: USDA zone 9b, about 278 days between hard freezes, across 5K acres of town.
- USDA zone
- 9b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 1
- Humboldt County normal — NOAA 1991–2020, nearest to this town
- First hard freeze (28°F)
- Dec 4
- Humboldt County normal — NOAA 1991–2020, nearest to this town
- Days between freezes
- ~278
- Humboldt 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 Humboldt County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 9b is Westhaven-Moonstone's average, not your lot's — a low corner or a tree line moves it. Against Westhaven-Moonstone's 278-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Westhaven-Moonstone
Each reading below is measured for Westhaven-Moonstone itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsWesthaven-Moonstone runs about 278 days between hard freezes (read from Humboldt County, the closest normal to Westhaven-Moonstone) — 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
MeasuredWesthaven-Moonstone 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 Westhaven-Moonstone is in
Westhaven-Moonstone sits in the Coast Range — EPA Level III, inside the wider Marine West Coast Forest. That is read at Westhaven-Moonstone's own centroid rather than borrowed from Humboldt County.
What Grows in Westhaven-Moonstone
Every plant below cleared Westhaven-Moonstone's own zone 9b and its 278-day season. Each card opens that plant's California profile. How we score.
Is it too late to plant in Westhaven-Moonstone?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Feb 1; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 1 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 4 — long-season crops need about 90 days of runway, quick greens only 30. In a climate this gentle, “too late” hardly applies — the question becomes which crops prefer the cooler months ahead.
What's on the federal record near Westhaven-Moonstone
Closest first, within ~10 miles of Westhaven-Moonstone. Listing isn't leaking, and distance isn't exposure.
- SCM AUTOBODY WORK & PAINTINGBrownfields · 0.6 mi
- 008N001E31K001HNitrate · 0.9 mi
- CRANNELL FORESTRY MAINTENANCE COMPLEXBrownfields · 1.9 mi
- CYPRESS GROVE CHEVRE - DAIRYBrownfields · 2.4 mi
- TRINIDAD CHEVRON/REDWOOD OIL COBrownfields · 3.1 mi
- Redwood Oil Co - Trinidad Chevron Gasoline StationUnderground Storage Tanks · 3.1 mi
- PACIFIC BELLBrownfields · 3.1 mi
- TRINIDAD HARBORBrownfields · 3.3 mi
- TELONICHER MARINE LAB HSUBrownfields · 3.3 mi
- 008N001W14R001HNitrate · 3.7 mi
- COUNTY OF HUMBOLDT PUBLIC WORKS MCKINLEYVILLE RD MAINTENANCE STATIONBrownfields · 4.0 mi
- LOUISIANA PACIFIC MCK AIRPORTBrownfields · 4.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Westhaven-Moonstone'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 Westhaven-Moonstone.
Total Sites
143
within ~10 miles of Westhaven-Moonstone
Risk Level
Moderate
Highest-severity
2 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Westhaven-Moonstone
Severity Distribution
within ~10 miles of Westhaven-Moonstone
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Westhaven-Moonstone, Brownfields runs higher than the national average — 120 sites within ~10 miles of Westhaven-Moonstone. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
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 Westhaven-Moonstone
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 Westhaven-Moonstone average
Your land is one point inside Westhaven-Moonstone
Everything above resolves to Westhaven-Moonstone as a whole — one PHZM band, read across 5K acres, with hard-freeze dates borrowed from Humboldt 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 Westhaven-Moonstone Average
Westhaven-Moonstone Average
- ●USDA Zones 9b, averaged across Westhaven-Moonstone
- ●One soil character for all of Westhaven-Moonstone
- ●Frost dates read at Westhaven-Moonstone's scale: Mar 1 to Dec 4
YOUR Parcel
- ✓Your exact zone, not Westhaven-Moonstone's 9b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Westhaven-Moonstone
Pull a site-specific report for your exact address in Westhaven-Moonstone, California — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Westhaven-Moonstone averages can't show:
We read public map data around Westhaven-Moonstone — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Westhaven-Moonstone average
How we know this about Westhaven-Moonstone
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 Humboldt 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 Westhaven-Moonstone
When does frost risk typically end in Westhaven-Moonstone?
The last hard freeze (28°F) in Westhaven-Moonstone typically lands around Mar 1, 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 22.
When is the first frost in Westhaven-Moonstone?
The first hard freeze (28°F) in Westhaven-Moonstone typically arrives around Dec 4, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 20, so the watching starts about Nov 4 — about 278 days after the spring freeze cleared.
How long is the growing season in Westhaven-Moonstone?
Measured between 28°F hard freezes, Westhaven-Moonstone sees about 278 frost-free days — roughly Mar 1 through Dec 4, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Mar 22 to Nov 20, about 243 days.
Is the soil safe to grow vegetables in Westhaven-Moonstone?
The federal record around Westhaven-Moonstone shows 143 documented sites, mostly Brownfields entries (120), the nearest Brownfields record about 0.6 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 Westhaven-Moonstone?
From about Nov 4 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 4 (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 4. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Westhaven-Moonstone's scale — its 9b band and its 278-day season. Your yard writes its own version of Westhaven-Moonstone'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 Westhaven-Moonstone’s own scale
5 of the readings below were taken at Westhaven-Moonstone's own scale — the 5,178 acres it covers and 143 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- Westhaven-Moonstone's own USDA hardiness band, zones 9bUSDA PHZM 2023
- 143 documented contamination sites on the federal record near Westhaven-Moonstone, the closest Brownfields record about 0.6 miles out from the town centreFederal environmental registers
- Westhaven-Moonstone's boundary and the 5,178 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 9b and a ~278-day seasonGrowable Ground crop-matching engine
- The ecoregion at Westhaven-Moonstone's own centroid, the Coast RangeUS EPA Level III Ecoregions
Inherited from a wider read
- The 28°F hard-freeze dates — Westhaven-Moonstone has no normal of its own, so its county's is the closest measured readfrom Humboldt County
- Soil character — no town-scale survey exists, so Westhaven-Moonstone's 5,178 acres read through its county's SSURGO summaryfrom Humboldt County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Humboldt 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 Humboldt County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Westhaven-Moonstone's 5,178 acreswhy one lot differs from the next →
- Which side of Westhaven-Moonstone you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 5,178 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.6 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 Westhaven-Moonstone-wide figureread your own land →
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