Kahului, Hawaii, sits in USDA hardiness zone 12b — a zone band wide enough that plant choice, not possibility, is the interesting question.
Among the crops suited to this profile: cassava, starfruit, allspice, and eggplant. The site-level story — soil, sun, drainage — decides the rest.
Even in Kahului, 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 Kahului 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 Kahului — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Kahului — the short answer
Kahului, Hawaii: USDA zone 12b, no 28°F killing freeze in Maui County’s record — the season is year-round, across 9K acres of town.
- USDA zone
- 12b
- USDA PHZM 2023
- Killing freeze
- None on record
- Maui County normal — NOAA RCC ACIS 1991–2020, nearest to this town
- Town area
- 9K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. The year-round finding is measured — Maui 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 Kahului's average, not your lot's — a low corner or a tree line moves it. Against Kahului'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 Kahului
Each reading below is measured for Kahului itself — here is what it means for a garden here, and the move an experienced grower makes about it.

Season length
From county recordsKahului has no station of its own, and Maui 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
MeasuredKahului 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 Kahului
Every plant below cleared Kahului'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 Kahului
Closest first, within ~10 miles of Kahului. Listing isn't leaking, and distance isn't exposure.
- MAUI WOOD TREATING CO LTDBrownfields · 1900 ft
- LOWE'S OF KAHULUI, HI #3279Brownfields · 0.6 mi
- SAFEWAY STORE #280Brownfields · 0.6 mi
- SUGAR MILL AUTO CARE CENTERUnderground Storage Tanks · 0.6 mi
- HALEAKALA TRANSPORTATION AND WAREHOUSEINGUnderground Storage Tanks · 0.6 mi
- RETHINK RECYCLING & REUSE CENTERBrownfields · 0.6 mi
- PETCO STORE #2145Brownfields · 0.6 mi
- CVS PHARMACY #17598 (INSIDE TARGET STORE T2660)Brownfields · 0.7 mi
- TARGET STORE T2660Brownfields · 0.7 mi
- HC&S - PUUNENEBrownfields · 0.8 mi
- HC&S - PUUNENEToxics Release Inventory · 0.8 mi
- HOME DEPOT STORE #1703Brownfields · 0.9 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Kahului'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 Kahului.
Total Sites
390
within ~10 miles of Kahului
Risk Level
Elevated
Highest-severity
4 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Kahului
Severity Distribution
within ~10 miles of Kahului
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 Kahului
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 Kahului average
Your land is one point inside Kahului
Everything above resolves to Kahului as a whole — one PHZM band, read across 9K acres, with hard-freeze dates borrowed from Maui 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 Kahului Average
Kahului Average
- ●USDA Zones 12b, averaged across Kahului
- ●One soil character for all of Kahului
- ●State-average frost dates
YOUR Parcel
- ✓Your exact zone, not Kahului's 12b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Kahului
Pull a site-specific report for your exact address in Kahului, Hawaii — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Kahului averages can't show:
We read public map data around Kahului — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Kahului average
How we know this about Kahului
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 Maui 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 Kahului
Is it too late to plant in Kahului?
No — Kahului has no station of its own, and Maui 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 Kahului?
It doesn't — Kahului has no station of its own, and the 1991–2020 record for Maui 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 Kahului?
Year-round — Kahului has no station of its own, and the 1991–2020 record for Maui 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 Kahului?
The federal record around Kahului is a meaningful one — 390 documented sites, mostly Underground Storage Tanks entries (217), the nearest Brownfields record about 0.4 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 Kahului's scale — its 12b band and its no killing freeze on record. Your yard writes its own version of Kahului'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 Kahului’s own scale
4 of the readings below were taken at Kahului's own scale — the 9,207 acres it covers and 390 documented sites around it; 5 are borrowed from a wider read, named and linked below.
Measured here
- Kahului's own USDA hardiness band, zones 12bUSDA PHZM 2023
- 390 documented contamination sites on the federal record near Kahului, the closest Brownfields record about 0.4 miles out from the town centreFederal environmental registers
- Kahului's boundary and the 9,207 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 — Kahului has no station of its own, and its county's 30-year record contains no 28°F killing freeze at allfrom Maui County
- Soil character — no town-scale survey exists, so Kahului's 9,207 acres read through its county's SSURGO summaryfrom Maui County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Maui 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 Maui County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Kahului's 9,207 acreswhy one lot differs from the next →
- Which side of Kahului you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 9,207 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields 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 Kahului-wide figureread your own land →
More in Hawaii
Wider growing context
What grows across HawaiiKahului sits outside our named growing regions, so Hawaii as a whole is its closest context here.
Nearby growing guides
