However, koa adapts to almost any of Hawaii's diverse environments indicating its potential elsewhere in the Pacific. Koa is found on all volcanic soil types of all geologic ages. It grows well in moderately to well-drained, medium to very strongly acid soils on both flatland and steep slopes. On dry, shallow, poorly drained soils koa's growth is slow and its form generally poor. This distribution is largely the result of land conversion to agriculture and ranching.
Cattle avidly graze koa seedlings, preventing regeneration.
Silviculture Propagation is most successful from seed. Koa seeds are durable and easy to store. They germinate after many years of storage if kept in a cool, dry place. The most effective method for improving seed germination is mechanical scarification. However, hot water soaking works well and is a more practical method.