Hawaii · zones 12a–12a
When to plant green beans in Hawaii.
Sow between Jan 1 to Feb 21 in a typical year, keyed to Hawaii's median last frost around Jan 1. A second, fall sowing fits Sep 16 to Oct 19. Dates below are state medians; your ZIP code shifts them by days to weeks.
The 2026 windows
Green Beans dates for a typical Hawaii season.
Direct sow
Jan 1 to Feb 21
Keyed to the ~Jan 1 last frost. Sow 1" deep, 3" apart.
Fall round
Sep 16 to Oct 19
Counted back from the ~Dec 31 first frost.
Harvest
~55 days later
~0.75 lb per plant over ~3 weeks.
Hawaii spans more than one climate: Zone 12 is the most common zone, but the state runs 12a to 12a. That's why the planner works from your ZIP code's frost dates, not your zone: mountain and coastal gardens in the same state can be three weeks apart.
Hawaii growing notes
Bush beans run through as many as 31 sowings a year here, fast enough that a Chinese rose beetle problem on one round is often gone by the time the next round comes up.
One stand, one flush, then it's the next row's turn
Bush beans go in an inch deep and close, about 3 inches apart, and move fast: a first picking around 55 days out, and a modest return of roughly three-quarters of a pound per plant. Unlike a vining crop that keeps setting fruit for months, a bush bean plant puts most of its pods on in one concentrated flush and tapers off within a couple of weeks. A single stand does not carry a household very far on its own, which is why up to 31 separate sowings go in across the year rather than one large planting: less about hedging against a failed stand, more about keeping a new flush coming in behind the last one.
The test for when a row is finished is in the picking itself. Once a stand that was giving double handfuls slows to a few pods every couple of days, it has entered its taper and is not coming back with a second flush. Pulling that row promptly, rather than nursing a spent stand along, keeps the relay going and denies aphids the tired, taper-stage leaves they favor most, right as the fresh seedlings from the next sowing are coming up a few weeks behind it.
Leaf damage with no bug in sight points to Chinese rose beetle
Chinese rose beetle is the insect to watch on beans here, and it rarely shows itself during a daytime check, since it feeds at night and retreats into the soil before sunrise. What a grower actually finds is the damage: leaves reduced to a lace of bare veins, with almost none of the softer green tissue left between them. That pattern alone identifies the culprit without spotting one, since nothing else here skeletonizes a leaf quite that fast overnight.
Catching the insect itself means checking after nightfall with a flashlight in hand, dropping whatever turns up into a jar of soapy water. A dim bulb left burning above a shallow tray of the same soapy water overnight becomes a trap on its own, since a faint glow pulls the beetles in where a bright light would send them away. With a new sowing of beans going into the ground every week or so, working a rose beetle check into the first couple of weeks after each planting catches the damage while the seedlings still have the least leaf area to lose.
A disease that needs a wet leaf, and two that don't
Anthracnose needs actual water to travel: rain splashing spores from an infected pod onto a clean one, or a picker working a wet row after rain and carrying it on wet hands. It shows as dark, sunken spots on the pods, sometimes with a faint pinkish ooze at the center on a humid morning. That makes it more of a problem on the wetter, windward side of a property, or after a run of rainy weeks, and the cheapest fix is free: stay out of the row until the leaves have dried.
Rust and powdery mildew do not play by that rule; both spread through humid air alone and do not need standing water to get established, so a bed on the drier, leeward side is not off the hook just because the soil stays dry underfoot. Rust shows first as tiny orange-brown flecks scattered across the underside of a leaf, rubbing off like dust on a fingertip, while powdery mildew shows as the familiar white coating on top. Either one thinning the leaves on a plant with only a couple of weeks to fill its pods costs real yield fast, so a quick look under a few leaves is worth doing the same day picking starts.
In Hawaii: watch for
The pests that find green beans here.
With about 364 frost-free days, bush bean spends longer in the ground here than in most of the country, which widens the window in which chinese rose beetle can find it. Scout weekly from midseason and act on the first signs.
Chinese rose beetle
Leaves chewed to lace between the veins, with no insect in sight by day.
Organic fix: Go out after dark with a jar of soapy water and pick them off, or hang a dim light over a soapy tray to trap them.
Orange or white spots on leaves late in the season.
Organic fix: Water at the base, space plants, spray neem.
Anthracnose
Sunken dark-red cankers on the pods, and leaf veins turning brick-red to black underneath.
Organic fix: Start with certified seed, water at the base, and stay out of the patch while the leaves are wet.
Your season math: Hawaii gives green beans about 364 frost-free days, and it needs roughly 55 days to a first harvest. That fits about 31 re-sown rounds across the season, so you can keep it coming instead of picking once.
Planting green beans in Hawaii: questions
When should I plant green beans in Hawaii?+
In a typical Hawaii year, sow green beans between Jan 1 to Feb 21, keyed to the state's median last frost around Jan 1. There's also a fall window: Sep 16 to Oct 19. Your exact dates shift with your ZIP code and microclimate.
What USDA zone is Hawaii?+
Hawaii spans zones 12a–12a, mostly zone 12. But frost dates, not zones, set planting time. The free planner uses your ZIP code's actual frost dates.
How many green beans plants do I need?+
Depends who you're feeding. The crop page has exact counts per household size, or the free planner does the math for your family in about 60 seconds.