Flower, unripe fruit and seeds. The bright white flowers have a wonderful gardenia and coconut aroma. The intensely orange-yellow colored pulp of the fruit, called nāʻū or nānū, was used to dye kapa (tapa) by early Hawaiians for the aliʻi.  A young, three-year-old semi-cultivated nāʻū that hasn't yet flowered. A mature cultivated Oʻahu nāʻū grown from seed (1990), originally from a Nānākuli tree that is now gone. Trunk and looking up through the canopy of perhaps the last wild nāʻū on Oʻahu.

Growth Requirements

General

    Nāʻū (Gardenia brighamii) is an excellent example of a Critically Endangered (IUCN) species now grown as a fairly common tree in private yards, botanical gardens and urban landscapes.

    Nāʻū is easy to grow and care for in the landscape and is not too particular about soil conditions. It does, however, prefer lots of sunlight to thrive. As a container plant, use at least a 15-gallon tub and add generous amounts of lava cinder with potting soil mix at about a 1:1 ratio. Cinders will ensure good drainage and add weight to the tub to avoid tipping over.

    Potted plants respond well to fertilizers, but avoid high nitrogen fertilizers, which may cause luxuriant growth but fewer flowers. Use a balanced slow-release fertilizer with minor elements every six months. Foliar feed monthly with kelp or fish emulsion, or a water-soluble fertilizer with a dilution of one-half to one-third of recommended strength. It also appreciates frequent applications of iron chelate and fertilizers for acid-loving plants (e.g., Miracid® by Miracle-Gro®). Apply at half or one-third strength according to the directions on the label for gardenias. 

    Cultivated plants flower more or less year-round with some brief rest periods.

Pests and Diseases

    It is prone to ants, scale, mealybugs, thrips, red spider mites and aphids. Black twig borers may cause minor damage at first, but must be treated immediately, or it can destroy the entire tree. Refer to the Pests & Diseases page for treatments.  

Special Features and Information

General

    Nāʻū or nānū (Gardenia brighamii) is one of several members of the Coffee family (Rubiaceae) native to the Hawaiian islands. It and the two other endemic Hawaiian gardenias, G. mannii found on Oʻahu, and G. remyi, found on Kauaʻi, Molokaʻi, Maui, and Hawaiʻi Island (Hilo and Puna districts), are all federally-listed as Critically Endangered (IUCN). 

    Gardenia brighamii is extremely rare and near extinction throughout its native habitat today. However, many botanists think it once grew on all the main Hawaiian Islands. It is originally recorded from Oʻahu (Waiʻanae Mountains and Nuʻuanu Valley in the southeastern Koʻolau Mountains), West Molokaʻi, Lāna`i (primarily at Kānepuʻu), West Maui (Olowalu), and the island of Hawaiʻi (Puʻuwaʻwa`a in North Kona) [Wagner et al. 1990].

    Today, the only known wild nā‘ū are on Lānaʻi within the Kānepu‘u Preserve, where several large trees are still alive. Until relatively recently, there were also four wild nā‘ū in the Southern Wai‘anae Mountains on O‘ahu. However, these are all now dead, with one dying in 2001 (probably from drought and competition with alien grasses), a second dying in 2005 (from a brushfire), the third dying in 2006 (presumably from a long battle with alien insects), and the last dying in 2023 (a few years after another brushfire scorched the surrounding forest). 

    Meanwhile, some progress has been made with nā‘ū restoration. The State’s PEP program has established a test planting of nā‘ū in Wai‘anae kai, while Ka‘ala Farm, Inc. has planted about a dozen nā‘ū within their Nānākuli Valley Cultural & Botanical Preserve and another dozen inside their Ka‘ala Kīpuka near The Cultural Learning Center at Ka‘ala. Refer to the 2021 USFWS 5-Year Review for other recovery efforts.

Hawaiian Name

    In modern times, we typically associate colors with light, such as the colors of the rainbow or red, green & blue (RGB) spectrum. However, not all indigenous peoples thought or spoke of colors in the same way. For example, there is no direct translation in Hawaiian for the English word "blue," though we usually refer to it as uli or uliuli, the color of the deep ocean. Hawaiian color words often reflect the source or origin of the color they represent. The term nā‘ū not only refers to the Hawaiian gardenia (Gardenia brighamii) but also describes the color of the dye extracted from its ripe fruits [Hawaiian Dictionaries]. This demonstrates the intricate and meaningful ways in which different cultures perceive and articulate colors. 

Etymology

    The generic name Gardenia was named in honor of Alexander Garden (1730-1791) of Charleston, South Carolina, who was a botanist, zoologist and physician [Gledhill 2008]. The specific epithet brighamii is named by Horace Mann, Jr. (1844-1868) in honor of William Tufts Brigham (1841-1926), geologist, botanist and the first director of the Bernice P. Bishop Museum, Honolulu, Hawaiʻi. Mann said in naming Gardenia brighamii, "I take great pleasure in dedicating this species to my friend and companion Mr. W. T. Brigham" [Welch 1868].