When to plant arugula in Hawaii
Hawaii is essentially frost-free (USDA zones 9b, 10a, 10b, 11a, 11b, 12a, 12b, 13a), so arugula timing there is set by heat and daylength rather than frost. As a cool-season crop, it does best in the cooler months (roughly October–March) and tends to bolt in summer heat.
Hawaii covers a wide range of climates, so your exact frost dates may differ from the state average by two weeks or more. For dates tuned to your town, use the calendar generator.
When to plant arugula in Hawaii: the short answer
For a spring planting, sow Dec 30 – Jan 18. Seeds germinate in soil from 40 to 75°F.
Your area is essentially frost-free, so planting dates are set by heat and daylength rather than frost. Treat the ranges below as broad season guides.
Cool-season crop: in a frost-free area grow it in the cooler months (roughly October to March) and expect bolting in summer heat.
Windows are ~1–2 week bands around each date. Frost dates are a statewide average from NOAA/NCEI normals; your town may differ by two weeks or more. Calendar year 2026.
How to grow arugula in Hawaii, step by step
- Prepare the bed. It needs six or more hours of sun for the best growth, though four to six hours in partial shade is enough and loose soil at least 8 inches deep, with a pH between 6.0 and 7.0. Dig in compost before planting.
- Sow outdoors (Dec 30 – Jan 18). Space plants about 4 inches apart in rows 10 inches apart, sowing seed ¼ inch deep. It handles frost well, so it can go out before the last frost date. As a cool-season crop it does best before summer heat arrives in Hawaii.
- Water and feed. Give it steady, even moisture, about an inch of water a week from rain or the hose.
- Watch for pests and problems. Pests: flea beetle, aphids, cabbage worm. Diseases and disorders: downy mildew, white rust.
- Harvest (from about Feb 3 – Feb 13). Arugula takes 30-40 days to reach harvest. One of the fastest crops - baby leaves in about 3 weeks. Turns sharp and bitter and bolts in heat, so it is a spring/fall green. Flea beetles love it; grow under mesh.
Figures come from our crop data; dates use Hawaii’s average frost dates. More in the full arugula growing guide.