Koloa, Hawaii, sits in USDA hardiness zone 12b — a zone band wide enough that plant choice, not possibility, is the interesting question.
Well-matched crops include cassava, starfruit, allspice, and eggplant, and the gap between "grows in the area" and "grows in your yard" is closed by soil, sun, and drainage.
Even in Koloa, 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 Koloa 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 Koloa — soil, climate, flood, and parcel records. How we handle your address.
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Koloa — the short answer
Koloa, Hawaii: USDA zone 12b, no 28°F killing freeze in Kauai County’s record — the season is year-round, across 800 acres of town.
- USDA zone
- 12b
- USDA PHZM 2023
- Killing freeze
- None on record
- Kauai County normal — NOAA RCC ACIS 1991–2020, nearest to this town
- Town area
- 800 acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. The year-round finding is measured — Kauai 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 12b is Koloa's average, not your lot's — a low corner or a tree line moves it. Against Koloa'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 Koloa
Each reading below is measured for Koloa itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsKoloa has no station of its own, and Kauai 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
MeasuredKoloa sits in USDA hardiness zone 12b.
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 Koloa
Every plant below cleared Koloa's own zone 12b and its 365-day season. Each card opens that plant's Hawaii profile. How we score.
What's on the federal record near Koloa
Closest first, within ~10 miles of Koloa. Listing isn't leaking, and distance isn't exposure.
- LORAN STATIONUnderground Storage Tanks · 400 ft
- IES Retail Poipu RoadUnderground Storage Tanks · 1800 ft
- KOLOA CENTRAL OFFICEUnderground Storage Tanks · 1900 ft
- KOLOA SHELL SERVICE INC.Underground Storage Tanks · 2000 ft
- HAWAIIAN TELCOM KOLOA CENTRAL OFFICEBrownfields · 2000 ft
- Kauai County Koloa Fire StationUnderground Storage Tanks · 2400 ft
- BORTHWICK KAUAI MORTUARYUnderground Storage Tanks · 2500 ft
- HADAMA SERVICEUnderground Storage Tanks · 0.5 mi
- UP TO DATE CLEANERS KAUAI INCBrownfields · 0.6 mi
- PAANAU VILLAGE APARTMENTSBrownfields · 0.6 mi
- UP-TO-DATE CLEANERS KAUAI, INC.Underground Storage Tanks · 0.6 mi
- 2-5427-01 Koloa W-A, Kauai, HINitrate · 0.6 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Koloa'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 Koloa.
Total Sites
242
within ~10 miles of Koloa
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of Koloa
Severity Distribution
within ~10 miles of Koloa
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Koloa, PFAS runs higher than the national average — 3 sites within ~10 miles of Koloa. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Check your specific parcel in Koloa
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 Koloa average
Your land is one point inside Koloa
Everything above resolves to Koloa as a whole — one PHZM band, read across 800 acres, with hard-freeze dates borrowed from Kauai 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 Koloa Average
Koloa Average
- ●USDA Zones 12b, averaged across Koloa
- ●One soil character for all of Koloa
- ●State-average frost dates
YOUR Parcel
- ✓Your exact zone, not Koloa's 12b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Koloa
Pull a site-specific report for your exact address in Koloa, Hawaii — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Koloa averages can't show:
We read public map data around Koloa — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Koloa average
How we know this about Koloa
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 Kauai 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 Koloa
Is it too late to plant in Koloa?
No — Koloa has no station of its own, and Kauai 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 Koloa?
It doesn't — Koloa has no station of its own, and the 1991–2020 record for Kauai 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 Koloa?
Year-round — Koloa has no station of its own, and the 1991–2020 record for Kauai 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 Koloa?
The federal record around Koloa is a meaningful one — 242 documented sites, mostly Underground Storage Tanks entries (137), the nearest Underground Storage Tanks record under a tenth of a mile 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 Koloa's scale — its 12b band and its no killing freeze on record. Your yard writes its own version of Koloa'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 Koloa’s own scale
4 of the readings below were taken at Koloa's own scale — the 800 acres it covers and 242 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- Koloa's own USDA hardiness band, zones 12bUSDA PHZM 2023
- 242 documented contamination sites on the federal record near Koloa, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Koloa's boundary and the 800 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 12b and a ~365-day seasonGrowable Ground crop-matching engine
Inherited from a wider read
- The frost finding — Koloa has no station of its own, and its county's 30-year record contains no 28°F killing freeze at allfrom Kauai County
- Soil character — no town-scale survey exists, so Koloa's 800 acres read through its county's SSURGO summaryfrom Kauai County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Kauai 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 Kauai County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Koloa's 800 acreswhy one lot differs from the next →
- Which side of Koloa you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 800 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks 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 Koloa-wide figureread your own land →
More in Hawaii
Wider growing context
What grows across HawaiiKoloa sits outside our named growing regions, so Hawaii as a whole is its closest context here.