Buy Koa in Honolulu, HI This endemic plant is often dominant in dry-wet forests on all of the main islands except Ni’ihau and Kaho’olawe. On O’ahu, koa is now restricted to mesic forests usually above 1000-1500 ft. Right now this plant is available at Hui Ku Maoli Ola Native Plant Nursery. in Public bookmarkswith koa-honolulu-hi