Consequently, smaller shrubby species can be planted in close proximity in a garden situation. Koa is a fast-growing tree that requires deep rich soils and full sun. Performance in coastal areas subject to constant salt air may be marginal. Koa will not do well in poor or poorly drained soils and is susceptible to coffee twig borers. Koa is easily cultivated and performs well.
Seeds germinate readily.
Enhance germination by soaking seeds in hot water for 24 hours, or lightly file seed to thin the seed coat. Seedlings grow quickly. Moderate to light.