Kō is sugar cane and was introduced by the ancient Hawaiians who grew some 40 different varieties of this large grass that was used as a source of sugar, fiber, and thatching.

Commercial sugar cane, first introduced to Hawai‘i in 1835, is a cultigen involving crosses of several varieties and species of Saccharum. At one time, sugar cane was the largest industry in the Hawaiian Islands, but today none is grown commercially anywhere in the islands—the last sugar mill (on Maui) closed in 2016.

The grass is propagated from short sections of cane that grow roots and new stems from the nodes. Rainfall at Nā Pōhaku o Hauwahine is problematical to sustain sugar cane growth, which commercially required a great amount of irrigation. Kō is planted here at the Kīhāpai and along the bottom of the gulch.