Alderpoint, California, sits in USDA hardiness zone 9a — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Crops well matched to these conditions include artichoke, fig, california poppy, and cabbage — though what thrives on any one site still turns on its specific soil, sun, and drainage.
Even in Alderpoint, 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 Alderpoint 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 Alderpoint — soil, climate, flood, and parcel records. How we handle your address.
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Alderpoint — the short answer
Alderpoint, California: USDA zone 9a, about 278 days between hard freezes, across 2K acres of town.
- USDA zone
- 9a
- 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
- 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 Humboldt County’s — the closest measured record, labelled as such rather than passed off as local.
Hardiness Zone Range
Zone 9a is Alderpoint's average, not your lot's — a low corner or a tree line moves it. Against Alderpoint's 278-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Alderpoint
Each reading below is measured for Alderpoint itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsAlderpoint runs about 278 days between hard freezes (read from Humboldt County, the closest normal to Alderpoint) — 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
MeasuredAlderpoint sits in USDA hardiness zone 9a.
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 Alderpoint is in
Alderpoint sits in the Klamath Mountains/California High North Coast Range — EPA Level III, inside the wider Northwestern Forested Mountains. That is read at Alderpoint's own centroid, and it is not what its county reads: Humboldt County is mostly Coast Range. The wider page above you is answering a different question about different ground.
What Grows in Alderpoint
Every plant below cleared Alderpoint's own zone 9a and its 278-day season. Each card opens that plant's California profile. How we score.
Is it too late to plant in Alderpoint?
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 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. 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 Alderpoint
Closest first, within ~10 miles of Alderpoint. Listing isn't leaking, and distance isn't exposure.
- LOUISIANA-PACIFIC CORP ALDERPOINT SAWMLBrownfields · 0.9 mi
- AT&T MOBILITYBrownfields · 5.1 mi
- PACIFIC BELLBrownfields · 5.5 mi
- GREEN LIGHT INCORPORATEDBrownfields · 7.0 mi
- MAZAR FARMS INCBrownfields · 7.8 mi
- HOMEGROWN FARMS INCBrownfields · 8.2 mi
- EMERALD HEALING HUMBLODTBrownfields · 9.3 mi
- VanceMining · 9.5 mi
- Hance PropertyMining · 9.5 mi
Measured from Alderpoint'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 Alderpoint.
Total Sites
10
within ~10 miles of Alderpoint
Risk Level
Low
Highest-severity
2 mining sites (prospects, none worked)
Severity Distribution
within ~10 miles of Alderpoint
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.
Check your specific parcel in Alderpoint
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 Alderpoint average
Your land is one point inside Alderpoint
Everything above resolves to Alderpoint as a whole — one PHZM band, read across 2K 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 Alderpoint Average
Alderpoint Average
- ●USDA Zones 9a, averaged across Alderpoint
- ●One soil character for all of Alderpoint
- ●Frost dates read at Alderpoint's scale: Mar 1 to Dec 4
YOUR Parcel
- ✓Your exact zone, not Alderpoint's 9a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Alderpoint
Pull a site-specific report for your exact address in Alderpoint, California — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Alderpoint averages can't show:
We read public map data around Alderpoint — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Alderpoint average
How we know this about Alderpoint
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 Alderpoint
When does frost risk typically end in Alderpoint?
The last hard freeze (28°F) in Alderpoint 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 Alderpoint?
The first hard freeze (28°F) in Alderpoint 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 Alderpoint?
Measured between 28°F hard freezes, Alderpoint 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 Alderpoint?
The federal record around Alderpoint is light — 10 documented sites across the 9 federal source types we checked, mostly Brownfields entries (8), the nearest Brownfields record about 0.9 miles 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 Alderpoint?
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 Alderpoint's scale — its 9a band and its 278-day season. Your yard writes its own version of Alderpoint'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 Alderpoint’s own scale
5 of the readings below were taken at Alderpoint's own scale — the 1,554 acres it covers and 10 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- Alderpoint's own USDA hardiness band, zones 9aUSDA PHZM 2023
- 10 documented contamination sites on the federal record near Alderpoint, the closest Brownfields record about 0.9 miles out from the town centreFederal environmental registers
- Alderpoint's boundary and the 1,554 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 9a and a ~278-day seasonGrowable Ground crop-matching engine
- Alderpoint sits in the Klamath Mountains/California High North Coast Range — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
Inherited from a wider read
- The 28°F hard-freeze dates — Alderpoint 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 Alderpoint's 1,554 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 Alderpoint's 1,554 acreswhy one lot differs from the next →
- Which side of Alderpoint you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,554 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.9 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 Alderpoint-wide figureread your own land →
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