Koba Onions are a Hawaiian green onion staple. The seeds originated from a local grower originally from Hong Kong, who gave the seeds over to the University to study and develop after a seed quarantine prevented the grower from receiving more seeds. University research found the green onion to be well received by the local growers in Hawaii - particularly due to the sturdy tips, dark green color, and good shelf life. The seed was then made available through the Seed Program in the Department of Horticulture at the University of Hawaii.
Green onions are in the Lily family (Allium fistulosum) and are an easy to grow perennial. When seeded in groups of 5-8 they will grow as a bunch, which can be harvested by cutting the tops and leaving the roots to reshoot. When using this cut and regrow method, be sure to fertilize and cultivate onion sprouts, as green onions do not like to compete with weeds. At the end of the season when the clump is full, you can dig up the entire plant, separate and replant as individual onions, which will again regrow into clumps. There will be plenty to share with friends and neighbors.
Koba Onions are a short day onion and will readily go to seed in Hawai'i. When planted too early in the year, plants may try to set seed before they mature. You can avoid this by waiting until April or May to start seed. Onions are shallow rooted and prefer moist, well drained and composted soil. They do not like to compete with weeds. When saving seed, be sure to give plants a stake or trellis to support large and heavy seed heads.
Maturity: 80-90 days from seed / 50- 60 days from clump harvesting