Mililani Mauka, Hawaii, sits in USDA hardiness zone 12a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Expect cassava, starfruit, allspice, and eggplant to be strong candidates here; the deciding factors on any one parcel stay local — soil, sun, and drainage.
Even in Mililani Mauka, 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 Mililani Mauka 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 Mililani Mauka — soil, climate, flood, and parcel records. How we handle your address.
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Mililani Mauka — the short answer
Mililani Mauka, Hawaii: USDA zone 12a, no 28°F killing freeze in Honolulu County’s record — the season is year-round, across 3K acres of town.
- USDA zone
- 12a
- USDA PHZM 2023
- Killing freeze
- None on record
- Honolulu County normal — NOAA RCC ACIS 1991–2020, nearest to this town
- Town area
- 3K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. The year-round finding is measured — Honolulu 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 Mililani Mauka's average, not your lot's — a low corner or a tree line moves it. Against Mililani Mauka'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 Mililani Mauka
Each reading below is measured for Mililani Mauka itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
From county recordsMililani Mauka has no station of its own, and Honolulu 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
MeasuredMililani Mauka 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 Mililani Mauka
Every plant below cleared Mililani Mauka'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 Mililani Mauka
Closest first, within ~10 miles of Mililani Mauka. Listing isn't leaking, and distance isn't exposure.
- 3-2859-02 Mililani II P6, Oahu, HINitrate · 2200 ft
- Tesoro 2Go #61057Underground Storage Tanks · 0.7 mi
- MILILANI MAUKA RSUUnderground Storage Tanks · 0.8 mi
- LONGS DRUG STORE #9890Brownfields · 0.8 mi
- 3-2800-01 Mililani I P1, Oahu, HINitrate · 0.8 mi
- LONGS DRUG STORE #4405Brownfields · 0.8 mi
- 3-2959-01 Schofield MW2-5, Oahu, HINitrate · 1.1 mi
- KALANI GARDENS APARTMENTSBrownfields · 1.1 mi
- TESLA - MILIANIBrownfields · 1.3 mi
- TARGET STORE T3032Brownfields · 1.5 mi
- Tesoro 2Go #61056Underground Storage Tanks · 1.7 mi
- GOODYEAR AUTO SERVICE CENTER 8024Underground Storage Tanks · 1.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Mililani Mauka'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 Mililani Mauka.
Sources Checked
within ~10 miles of Mililani Mauka
Severity Distribution
within ~10 miles of Mililani Mauka
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Mililani Mauka, two things run higher than the national average within ~10 miles of Mililani Mauka — Superfund (22 sites) and PFAS (11 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Superfund: Superfund sites represent the most severe contamination in the federal system.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Check your specific parcel in Mililani Mauka
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 Mililani Mauka average
Your land is one point inside Mililani Mauka
Everything above resolves to Mililani Mauka as a whole — one PHZM band, read across 3K acres, with hard-freeze dates borrowed from Honolulu 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 Mililani Mauka Average
Mililani Mauka Average
- ●USDA Zones 12a, averaged across Mililani Mauka
- ●One soil character for all of Mililani Mauka
- ●State-average frost dates
YOUR Parcel
- ✓Your exact zone, not Mililani Mauka's 12a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Mililani Mauka
Pull a site-specific report for your exact address in Mililani Mauka, Hawaii — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Mililani Mauka averages can't show:
We read public map data around Mililani Mauka — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Mililani Mauka average
How we know this about Mililani Mauka
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 Honolulu 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 Mililani Mauka
Is it too late to plant in Mililani Mauka?
No — Mililani Mauka has no station of its own, and Honolulu 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 Mililani Mauka?
It doesn't — Mililani Mauka has no station of its own, and the 1991–2020 record for Honolulu 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 Mililani Mauka?
Year-round — Mililani Mauka has no station of its own, and the 1991–2020 record for Honolulu 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 Mililani Mauka?
The federal record around Mililani Mauka runs heavier than most — 663 documented sites, mostly Underground Storage Tanks entries (312), the nearest Nitrate record about 0.4 miles out — so test the soil before planting food in the ground, and raised beds with clean imported soil grow well in the meantime. Even here, proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what's recorded and where.
Everything above is measured at Mililani Mauka's scale — its 12a band and its no killing freeze on record. Your yard writes its own version of Mililani Mauka'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 Mililani Mauka’s own scale
4 of the readings below were taken at Mililani Mauka's own scale — the 2,556 acres it covers and 663 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- Mililani Mauka's own USDA hardiness band, zones 12aUSDA PHZM 2023
- 663 documented contamination sites on the federal record near Mililani Mauka, the closest Nitrate record about 0.4 miles out from the town centreFederal environmental registers
- Mililani Mauka's boundary and the 2,556 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 — Mililani Mauka has no station of its own, and its county's 30-year record contains no 28°F killing freeze at allfrom Honolulu County
- Soil character — no town-scale survey exists, so Mililani Mauka's 2,556 acres read through its county's SSURGO summaryfrom Honolulu County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Honolulu 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 Honolulu County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Mililani Mauka's 2,556 acreswhy one lot differs from the next →
- Which side of Mililani Mauka you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 2,556 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate record about 0.4 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 Mililani Mauka-wide figureread your own land →
More in Hawaii
Wider growing context
What grows across HawaiiMililani Mauka sits outside our named growing regions, so Hawaii as a whole is its closest context here.
Nearby growing guides