[1] The garden was established in 1972 on Maui's northern coast, with rugged black lava seascapes, and is surrounded by one of Hawaiʻi's last undisturbed hala (Pandanus tectorius) forests.

Today the garden contains accessions of approximately 150 varieties of breadfruit collected from field expeditions to over 17 Pacific island groups in Polynesia, Micronesia, and Melanesia, as well as Indonesia, the Philippines, and the Seychelles.

Other garden holdings include bamboo, banana, calabash, coconut, kava, kamani (Calophyllum inophyllum), loʻulu (Pritchardia arecina), sugarcane, taro, turmeric, vanilla, and bitter yam (Dioscorea bulbifera).

[2] Kahanu Garden also contains the 3-acre (12,000 m2) Piʻilanihale Heiau, a National Historic Landmark believed to be the largest ancient temple in the Hawaiian Islands.

Wings were later added and rededicated during the 16th century, possibly after high chief Piʻilani from western Maui conquered the beautiful, fertile, well-watered, and heavily populated Hāna region, thereby unifying the whole island.