Hamakua Coast & Hilo spans USDA hardiness zones 12a-12b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
The Big Island's rain-fed windward coast — 12a-12b, frost never, and some of the wettest farm country in the United States; tropical fruit, taro, and vanilla where Kona's dry leeward slopes grow coffee.
Hamakua Coast & Hilo spans Hawaii.
Your yard isn't all of Hamakua Coast & Hilo.
Hamakua Coast & Hilo spans USDA zones 12a-12b, but your parcel sits in exactly one — and slope, tree cover, and low spots nudge it further. 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 Hamakua Coast & Hilo — soil, climate, flood, and parcel records. How we handle your address.
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Hamakua Coast & Hilo — the short answer
Hamakua Coast & Hilo: USDA zones 12a-12b, 365 frost-free days, in Hawaii.
- USDA zones
- 12a-12b
- USDA PHZM 2023, aggregated over the footprint
- Frost-free season
- 365 days
- NOAA Regional Climate Centers ACIS, 1991–2020
- Towns
- 7
- US Census TIGER/Line 2025
- Region type
- Town cluster
- Growable Ground growing-region registry
Region boundary: Growable Ground growing-region registry — curated county clusters, EPA Level III ecoregions, and town clusters drawn finer than any county. Where a region publishes no measured season, no season figure is shown.
Hardiness Zone Range
What Grows in Hamakua Coast & Hilo
Plants matched to Hamakua Coast & Hilo's USDA zones 12a-12b, ordered by how much hardiness margin each has across the region — the ones with room to spare at both ends of this band lead. Each links to its full growing profile.
Native Plants of Hamakua Coast & Hilo
Plants the USDA PLANTS Database documents as native and present in this region’s state, kept only where the published hardiness range meets Hamakua Coast & Hilo’s USDA zones 12a-12b — closest range match first. Presence is recorded by state, so a plant can be documented across the state and still be scarce in your corner of the region.
Browse all US-native plants by state & zone →The ground around Hamakua Coast & Hilo
The USDA soil survey maps this ground county by county. These are those records weighted by land area across the county containing Hamakua Coast & Hilo — the ground Hamakua Coast & Hilo sits in, read at the only grain the survey publishes.
In the county containing Hamakua Coast & Hilo, the ground is predominantly Andisols, at 72% of mapped acres, followed by Histosols (22%), Entisols (3%) and Inceptisols (2%). Six soil orders appear in that record, which is the honest reason a regional soil answer only goes so far. The most extensive named soils are Kaiwiki, Keei, and Honokaa.
60% of those acres are well drained, and another 18% excessively drained, 8% moderately well drained. Topsoil pH runs 5.4–7.0 in that county’s own record. 3% of the footprint is classed prime farmland.
Soil order
Andisols
Drainage
Well drained
Topsoil pH
5.4–7.0
Hydric soils
2%
Soil changes across a driveway, so which of these your own ground sits on is a parcel question rather than a regional one. soil types explained.
USDA NRCS SSURGO via Soil Data Access
What this means for growing in Hamakua Coast & Hilo
The soil survey reads this ground county by county, and the readings above are the record for the county containing Hamakua Coast & Hilo. Here is what they mean for a garden here — and the move an experienced grower makes about each one.
Drainage
From county records60% of the mapped acres across the county containing Hamakua Coast & Hilo are well drained — ground that drains quickly. The survey maps this ground county-wide, so it describes the setting Hamakua Coast & Hilo sits in rather than the valley floor alone.
The upside is soil you can work early in spring and roots that never drown; the cost is that fast-draining ground dries out fast and leaches nutrients away before plants can use them.
Work in compost and mulch to hold moisture and feed, and water more often in short doses than deep and rarely.
USDA NRCS SSURGO
Surface pH
From county recordsTopsoil across the county containing Hamakua Coast & Hilo runs pH 5.4–7.0 — near neutral in the one record covering it.
This is the range most vegetables prefer — one correction you probably do not have to make, which is genuinely good news for a new bed.
Keep it there with compost rather than lime or sulfur, and only amend if your own soil test says otherwise.
USDA NRCS SSURGO
Safe to Grow Here?
What the federal record shows across Hamakua Coast & Hilo — and how to grow with it.
Across Hawaii County, which contains Hamakua Coast & Hilo, the federal record holds 734 documented sites, mostly Underground Storage Tanks (432), Brownfields (217) and Nitrate (50).
That is the containing county's count — this region is a smaller piece of that ground, so it is context, not a reading of any one lot. Open the map outlined to Hamakua Coast & Hilo to see which records sit where you actually grow.
Sources Checked
Summed across the county containing Hamakua Coast & Hilo
A note from Gnorman
What an experienced grower watches for around here
In and around Hamakua Coast & Hilo, PFAS runs higher than the national average — 8 sites across the county containing Hamakua Coast & Hilo. That's not a problem with your land — it's information about 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.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
Your land is one point inside Hamakua Coast & Hilo
Everything above resolves to Hamakua Coast & Hilo as a whole — a footprint spanning USDA zones 12a-12b. Your parcel sits in exactly one of them. 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 region 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 regional average.
Your Lot vs Hamakua Coast & Hilo Average
Hamakua Coast & Hilo Average
- ●USDA Zones 12a-12b, averaged across Hamakua Coast & Hilo
- ●One soil character for all of Hamakua Coast & Hilo
- ●State-average frost dates
YOUR Parcel
- ✓Your exact zone, not Hamakua Coast & Hilo's 12a-12b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Hamakua Coast & Hilo
Pull a site-specific report for your exact address in Hamakua Coast & Hilo — soil, sun, drainage, frost risk, contamination, and scored plant recommendations.
Three things about your lot that Hamakua Coast & Hilo averages can't show:
We read public map data around Hamakua Coast & Hilo — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not Hamakua Coast & Hilo average
How we know this about Hamakua Coast & Hilo
The boundary: the region's own towns — a footprint finer than any county, because the county average would misread this microclimate. Growing regions have no official boundary, so this footprint is our published one, and every figure on this page was measured over the towns inside it rather than borrowed from the state around it.
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, aggregated across the footprint; the growing season from NOAA Regional Climate Centers ACIS 1991–2020 28°F normals, read at each member’s own record; boundaries from US Census TIGER/Line 2025; the contamination record from the federal sources named in that beat above; the soil from the USDA NRCS SSURGO survey, read at each member county’s own record and weighted to this footprint by land area. Where a member carries no record of its own, it is absent from the figure rather than filled in.
Common questions about Hamakua Coast & Hilo
What hardiness zone is Hamakua Coast & Hilo?
Hamakua Coast & Hilo spans USDA hardiness zones 12a-12b, aggregated from the USDA Agricultural Research Service Plant Hardiness Zone Map 2023 across the region's own towns. Zones reflect average annual extreme minimum temperatures from 1991–2020 data.
What grows well in Hamakua Coast & Hilo?
Hamakua Coast & Hilo's conditions suit plants such as Plumeria. What actually thrives on any one site still turns on its specific soil, sun, and drainage — we score each plant against the real conditions at your address.
How is Hamakua Coast & Hilo defined?
Hamakua Coast & Hilo is a true microclimate — smaller than the county that contains it, with a growing reality of its own. So this page is built from the region's own 7 towns, each carrying its own hardiness zone and frost record, rather than from a county average measured somewhere else.
Which states does Hamakua Coast & Hilo cover?
Hamakua Coast & Hilo spans Hawaii. Each state's full growing guide is linked on this page.
What other growing regions cover the same states?
Kona & Hawaii Island, Maui Upcountry, Waimea & Kohala, and Windward Oahu (Kailua–Kaneohe) share at least one state with Hamakua Coast & Hilo. Growing regions overlap and interlock — a single address can sit inside more than one, which is why the precise read is always the parcel, not the region.
What this page reads at Hamakua Coast & Hilo’s own scale
5 of the readings below were taken at Hamakua Coast & Hilo's own scale — the zone 12a-12b band across its footprint and 734 documented federal contamination records across its one county, 734 of them in Hawaii County alone; one is borrowed from a wider read, named and linked below.
Measured here
- The USDA hardiness band 12a-12b aggregated across all 7 towns in the footprintUSDA PHZM 2023
- The boundary itself — the 7 towns this region is curated fromGrowable Ground subregion registry
- The growing character that makes this region distinct from the states it crossesGrowable Ground subregion registry
- The federal contamination record over the whole footprint — 734 documented federal contamination records across its one county, 734 of them in Hawaii County aloneEPA, USGS and USDA federal site records
- The soil order mix across the footprint — 72% Andisols, topsoil pH 5.4–7.0, area-weighted across its one mapped countyUSDA NRCS SSURGO
Inherited from a wider read
- The candidate plant list — its state's curated sets, merged and filtered to zones 12a-12bfrom Hawaii
What this page can’t tell you
- Frost dates — they swing too far across a footprint this size to quote as one regional numberfrost dates explained →
- Which of those soils your own ground sits on — the survey maps them county-wide, and they change across a drivewaysoil types explained →
- The soil pH, drainage, sun hours, and frost pockets on one specific lotwhy one lot differs from the next →
Explore Hamakua Coast & Hilo
State growing guides
Towns in this region
The county containing this region
Other growing regions across Hawaii
Volcanic slopes that never freeze at the shore and climb through every zone to the summits — on the Kona side, morning sun and afternoon cloud ripen coffee, macadamia, and tropical fruit.
The cool green shoulder of Haleakala — Kula onions, protea, and strawberries thrive in mountain air a world apart from the tropical shore below.
Paniolo country on Kohala's green saddle — Waimea's cool 11a upland pastures and truck farms sit a felt climate apart from the 12b coast towns at the island's northern tip; the Big Island's cool-season vegetable heart.
Oahu's wet green side — the Koolau's windward foot from Waimanalo to Laie, a uniform 12b where trade-wind rain grows banana, breadfruit, and taro with little irrigation, a world away from the leeward plain's dry heat.