Seed Starting Calendar for Hawaii (2027): When to Start Seeds

Q: Does Hawaii get frost?

47 of 49 NOAA stations in Hawaii record no spring freeze in the 1991 to 2020 normals, including Honolulu. The exception is high ground: Mauna Loa 5 NNE (11,179 feet) has a median last frost of April 12. Planting there follows the season and elevation rather than a frost countdown.

Q: What does University of Hawaii at Manoa CTAHR Cooperative Extension say about planting dates in Hawaii?

University of Hawaii at Manoa CTAHR Cooperative Extension's Home Gardening in Hawaii puts it this way: "Table 1 shows a diagram of the preferred months for planting vegetable crops within three arbitrary elevation ranges." The guide is linked below with the date it was read (September 21, 2026).

Q: How early do I sow transplants in Hawaii?

By the crop's time from seed to transplant, counted back from the month it goes in the ground. UNH Extension gives 8 to 10 weeks for peppers and eggplant, 6 to 8 for tomatoes and basil, 4 to 6 for broccoli, cabbage and kale, and 3 to 4 for cucumbers and squash.

Q: How long do seedlings need to harden off?

About two weeks. University of Missouri Extension: "Hardening should be started about two weeks before planting in the garden." University of Minnesota Extension adds that seedlings should go out on a cloudy day or in the late afternoon.

Planting months

University of Hawaii at Manoa CTAHR Cooperative Extension planting months for Hawaii

In Hawaii the planting calendar runs by the month more than by a frost date, and the extension publishes those months region by region. Each filled cell is a month the guide gives for planting that crop.

Low elevations (0 to 1,000 feet)

Crop	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
tomato	Jan	Feb	Mar	Apr					Sep	Oct	Nov	Dec
eggplant	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
broccoli	Jan	Feb	Mar	Apr					Sep	Oct	Nov	Dec
cabbage (head)	Jan	Feb							Sep	Oct	Nov	Dec
lettuce (Mignonette)	Jan	Feb	Mar	Apr					Sep	Oct	Nov	Dec
carrot	Jan	Feb	Mar	Apr					Sep	Oct	Nov	Dec
beets	Jan	Feb	Mar	Apr					Sep	Oct	Nov	Dec
radish	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
beans (bush green)	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
sweet corn	Jan	Feb	Mar	Apr					Sep	Oct	Nov	Dec
peas (Chinese edible pod)											Nov	Dec

Planting months from University of Hawaii at Manoa CTAHR Cooperative Extension, Home Gardening in Hawaii, read 2026-09-21. Tomatoes in Low elevations: January, February, March, April, September, October, November and December.

Last frost

Last spring frost dates in Hawaii

Honolulu, Hilo, Kahului, Kawaihae and Barking Sands on Kauai record no spring freeze at all; in Hawaii elevation and season, not frost, set the planting months, and cool crops do best in the low-elevation winter.

Three dates per station from the NOAA 1991 to 2020 normals. The median is the date half of springs run past. The last column is the date the last 32°F night has passed by in 9 years out of 10, the one to hold tender transplants for.

Station	Elevation	Early (1 in 10 years later than this)
HonoluluHonolulu Intl Airport, USW00022521	7 ft	No spring 32°F freeze in the 1991 to 2020 record
HiloHilo Intl Airport, USW00021504	38 ft	No spring 32°F freeze in the 1991 to 2020 record
KawaihaePuukohola Heiau 98.1, USC00518422	133 ft	No spring 32°F freeze in the 1991 to 2020 record
Barking SandsBarking Sands, USW00022501	13 ft	No spring 32°F freeze in the 1991 to 2020 record
Kahului AirportKahului Airport, USW00022516	51 ft	No spring 32°F freeze in the 1991 to 2020 record

Extension guide

What University of Hawaii at Manoa CTAHR Cooperative Extension advises

University of Hawaii at Manoa CTAHR Cooperative Extension publishes the planting guide Hawaii gardeners work from, Home Gardening in Hawaii (B-91).

“Table 1 shows a diagram of the preferred months for planting vegetable crops within three arbitrary elevation ranges.”

University of Hawaii at Manoa CTAHR Cooperative Extension, Home Gardening in Hawaii, quoted exactly.

“Broccoli and the cabbages (head, spoon, and Chinese) are excellent garden crops at low elevations during winter, and at high elevations they thrive the year around.”

University of Hawaii at Manoa CTAHR Cooperative Extension, on broccoli, quoted exactly.