Fern Acres, Hawaii, sits in USDA hardiness zone 12a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Growers here do well with cassava, starfruit, allspice, and eggplant — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Even in Fern Acres, 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 Fern Acres 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 Fern Acres — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Fern Acres — the short answer
Fern Acres, Hawaii: USDA zone 12a, no 28°F killing freeze in Hawaii County’s record — the season is year-round, across 4K acres of town.
- USDA zone
- 12a
- USDA PHZM 2023
- Killing freeze
- None on record
- Hawaii County normal — NOAA RCC ACIS 1991–2020, nearest to this town
- Town area
- 4K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. The year-round finding is measured — Hawaii County’s 30-year record, the closest to this town, contains no 28°F killing freeze — never inferred from missing dates.
Hardiness Zone Range
Zone 12a is Fern Acres's average, not your lot's — a low corner or a tree line moves it. Against Fern Acres's no killing freeze on record, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Fern Acres
Each reading below is measured for Fern Acres itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsFern Acres has no station of its own, and Hawaii County’s 30-year record — the closest to it — carries no 28°F killing freeze at all — 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
MeasuredFern Acres sits in USDA hardiness zone 12a.
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
What Grows in Fern Acres
Every plant below cleared Fern Acres's own zone 12a and its 365-day season. Each card opens that plant's Hawaii profile. How we score.
What's on the federal record near Fern Acres
Closest first, within ~10 miles of Fern Acres. Listing isn't leaking, and distance isn't exposure.
- MOUNTAIN VIEW ELEMENTARY SCHOOLBrownfields · 3.5 mi
- MOUNTAIN VIEW CENTRAL OFFICEUnderground Storage Tanks · 3.5 mi
- TATSUO KIMOTOUnderground Storage Tanks · 3.6 mi
- HIRANO STOREUnderground Storage Tanks · 5.1 mi
- HAWAIIAN BEACHESPFAS · 5.6 mi
- Maika'i 76Underground Storage Tanks · 6.0 mi
- MINIT STOP KEAAUUnderground Storage Tanks · 6.6 mi
- HAWAIIAN MACADAMIA NUT SERVICES, LLC KEAAUBrownfields · 6.6 mi
- LONGS DRUG STORE #6870Brownfields · 6.8 mi
- PUNA SUGAR COMPANY, LIMITEDUnderground Storage Tanks · 7.0 mi
- MIKO MEATS SLAUGHTER HOUSEUnderground Storage Tanks · 7.0 mi
- OLAA-MOUNTAIN VIEWPFAS · 7.1 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Fern Acres'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 Fern Acres.
Total Sites
47
within ~10 miles of Fern Acres
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of Fern Acres
Severity Distribution
within ~10 miles of Fern Acres
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Fern Acres, Toxics Release Inventory runs higher than the national average — 3 sites within ~10 miles of Fern Acres. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Check your specific parcel in Fern Acres
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 Fern Acres average
Your land is one point inside Fern Acres
Everything above resolves to Fern Acres as a whole — one PHZM band, read across 4K acres, with hard-freeze dates borrowed from Hawaii 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 Fern Acres Average
Fern Acres Average
- ●USDA Zones 12a, averaged across Fern Acres
- ●One soil character for all of Fern Acres
- ●State-average frost dates
YOUR Parcel
- ✓Your exact zone, not Fern Acres's 12a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Fern Acres
Pull a site-specific report for your exact address in Fern Acres, Hawaii — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Fern Acres averages can't show:
We read public map data around Fern Acres — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Fern Acres average
How we know this about Fern Acres
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 Hawaii 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 Fern Acres
Is it too late to plant in Fern Acres?
No — Fern Acres has no station of its own, and Hawaii County's 30-year record, the closest to it, holds no 28°F killing freeze, so the growing season is year-round and there is no last-frost date to wait for. Planting is paced by rainfall, heat and daylength instead of by frost: start heat-lovers any month, and time cool-season crops (lettuce, brassicas, peas) for the cooler, wetter half of the year or for higher ground. Succession sowing every few weeks works all year, so the limit is what you can keep watered and harvested, not the calendar.
When does frost risk typically end in Fern Acres?
It doesn't — Fern Acres has no station of its own, and the 1991–2020 record for Hawaii County, the nearest to it, carries no 28°F killing freeze at all, so there is no spring frost date to plant after. Cold still matters with elevation: the higher you garden, the cooler the nights, and a few tropical crops sulk below about 60°F even where they never freeze.
How long is the growing season in Fern Acres?
Year-round — Fern Acres has no station of its own, and the 1991–2020 record for Hawaii County, the closest to it, contains no 28°F killing freeze, so there is no season to measure between freezes. What paces planting instead is heat, rainfall and daylength: the hottest, wettest stretch is the hard part for cool-season crops, not winter. Elevation is the one real exception — the higher you garden, the colder the nights get.
Is the soil safe to grow vegetables in Fern Acres?
The federal record around Fern Acres is a meaningful one — 47 documented sites, mostly Brownfields entries (20), the nearest Brownfields record about 3.5 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.
Everything above is measured at Fern Acres's scale — its 12a band and its no killing freeze on record. Your yard writes its own version of Fern Acres'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 Fern Acres’s own scale
4 of the readings below were taken at Fern Acres's own scale — the 4,357 acres it covers and 47 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- Fern Acres's own USDA hardiness band, zones 12aUSDA PHZM 2023
- 47 documented contamination sites on the federal record near Fern Acres, the closest Brownfields record about 3.5 miles out from the town centreFederal environmental registers
- Fern Acres's boundary and the 4,357 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 12a and a ~365-day seasonGrowable Ground crop-matching engine
Inherited from a wider read
- The frost finding — Fern Acres has no station of its own, and its county's 30-year record contains no 28°F killing freeze at allfrom Hawaii County
- Soil character — no town-scale survey exists, so Fern Acres's 4,357 acres read through its county's SSURGO summaryfrom Hawaii County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Hawaii County
- The growing challenges every Hawaii grower plans around — written at state scale, so they stay on the state guidefrom Hawaii
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Hawaii County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Fern Acres's 4,357 acreswhy one lot differs from the next →
- Which side of Fern Acres you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 4,357 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 3.5 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 Fern Acres-wide figureread your own land →