Wailua, Hawaii, sits in USDA hardiness zone 12b — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
On paper, cassava, starfruit, allspice, and eggplant all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Even in Wailua, 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 Wailua 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 Wailua — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Wailua — the short answer
Wailua, Hawaii: USDA zone 12b, no 28°F killing freeze in Kauai County’s record — the season is year-round, across 983 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
- 983 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 Wailua's average, not your lot's — a low corner or a tree line moves it. Against Wailua'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 Wailua
Each reading below is measured for Wailua itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsWailua 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
MeasuredWailua 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 Wailua
Every plant below cleared Wailua'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 Wailua
Closest first, within ~10 miles of Wailua. Listing isn't leaking, and distance isn't exposure.
- RAINBOW SHELLUnderground Storage Tanks · 1600 ft
- COCO PALMS HOTELUnderground Storage Tanks · 1800 ft
- KAUAI COCONUT BEACH RESORTUnderground Storage Tanks · 2600 ft
- 2-0320-01 Nonou W-A, Kauai, HINitrate · 0.8 mi
- LONGS DRUG STORE #9952Brownfields · 0.9 mi
- NO DELAY SERVICE STATIONUnderground Storage Tanks · 1.0 mi
- kauai County KAPAA FIRE STATIONUnderground Storage Tanks · 1.0 mi
- WAILUA TREATMENT PLANTUnderground Storage Tanks · 1.1 mi
- PPG ARCHITECTURAL COATINGS (KAPAA)Brownfields · 1.3 mi
- Arzadon Industrial Park Cardlock Site #7Underground Storage Tanks · 1.4 mi
- KAZU MORITA SERVICEUnderground Storage Tanks · 1.5 mi
- OTSUKA SALES & SERVICE, LTD.Underground Storage Tanks · 1.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Wailua'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 Wailua.
Total Sites
210
within ~10 miles of Wailua
Risk Level
Elevated
Highest-severity
2 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Wailua
Severity Distribution
within ~10 miles of Wailua
Highest-Severity Sites
Know Before You Grow
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
- •Near a brownfield, raised beds of imported soil give your food clean ground.
- •On a private well, test for nitrates: above 10 mg/L the water needs treatment before irrigating.
Check your specific parcel in Wailua
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 Wailua average
Your land is one point inside Wailua
Everything above resolves to Wailua as a whole — one PHZM band, read across 983 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 Wailua Average
Wailua Average
- ●USDA Zones 12b, averaged across Wailua
- ●One soil character for all of Wailua
- ●State-average frost dates
YOUR Parcel
- ✓Your exact zone, not Wailua's 12b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Wailua
Pull a site-specific report for your exact address in Wailua, Hawaii — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Wailua averages can't show:
We read public map data around Wailua — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Wailua average
How we know this about Wailua
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 Wailua
Is it too late to plant in Wailua?
No — Wailua 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 Wailua?
It doesn't — Wailua 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 Wailua?
Year-round — Wailua 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 Wailua?
The federal record around Wailua is a meaningful one — 210 documented sites, mostly Underground Storage Tanks entries (114), the nearest Underground Storage Tanks record about 0.3 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 Wailua's scale — its 12b band and its no killing freeze on record. Your yard writes its own version of Wailua'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 Wailua’s own scale
4 of the readings below were taken at Wailua's own scale — the 983 acres it covers and 210 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- Wailua's own USDA hardiness band, zones 12bUSDA PHZM 2023
- 210 documented contamination sites on the federal record near Wailua, the closest Underground Storage Tanks record about 0.3 miles out from the town centreFederal environmental registers
- Wailua's boundary and the 983 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 — Wailua 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 Wailua's 983 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 Wailua's 983 acreswhy one lot differs from the next →
- Which side of Wailua you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 983 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.3 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 Wailua-wide figureread your own land →
More in Hawaii
Wider growing context
What grows across HawaiiWailua sits outside our named growing regions, so Hawaii as a whole is its closest context here.
Nearby growing guides