Kokia drynarioides has, perhaps, one of the most spectacular flowers of all our native flora. Note the large bracts at the base of kokia's flower buds (Photograph courtesy of Forest & Kim Starr CC BY 2.0). A flowering cultivated tree on Hawai‘i Island.

Growth Requirements

General

    Kokia drynarioides can be a challenging tree to maintain in a landscape. Generally, cultivated plants on Maui and Hawai‘i Island survive longer than those on O‘ahu, and those in non-urban settings survive longer than those planted in urban settings. We believe these differences may be the result of soil characteristics since potted koki‘o on O‘ahu often survive longer than those planted in the ground. One possible explanation for this survival difference is that the soils on O‘ahu are often more clay-dominant compared to those on Maui and Hawai‘i Island, which are mostly basalt lava or cinder. Another possibility is that the soils on O‘ahu are more likely to host harmful alien microbes than those on Maui and Hawai‘i Island. Whatever the cause, if you find your koki‘o dying after only a few years in the ground, you may want to consider: (1) Maintaining it as a container plant; just be sure to continually increase the container size as the plant grows since Kerin E. Lilleeng-Rosenberger states that "it is important that these plants do not become root-bound at any time in their development; this can result in a poor root system.", or (2) Growing the other koki‘o species, Kokia kauaiensis, from Kauaʻi, which may be better adapted to clay-dominant soils.

    With that preface, let's continue. Despite being naturally found at elevations of 1,500 to 2,600 feet (460 to 900 m), kokiʻo can be successfully grown and will flower at much lower elevations (e.g., Waimea Valley and Pearl City, Oʻahu). It does best in a site with full sunlight for all or most of the day, but can tolerate partial shade. However, we've found providing a new planting with temporary shade can be beneficial until the tree is established. 

    Kokiʻo does better with big infrequent waterings rather than light daily showers, and, once established, the plant should be watered sparingly. Kokiʻo is tolerant of drought after its first year but may lose many or all of its leaves during dry periods. Kokiʻo is intolerant of constantly wet soil (a common cause of death), and the soil at the planting site should drain rapidly. If the soil drains poorly, consider another planting site or create a mound or ridge on which to plant your kokiʻo.

    Kokia drynarioides often benefit from either a monthly feeding with an organic or inorganic foliar fertilizer at the half recommended strength, or three- or six-month applications of a balanced controlled-release fertilizer with minor elements. Work the fertilizer into the soil, but do not apply any near the base of the tree. 

    Kokiʻo grows at a moderate pace in the ground, and you should expect about a three-foot tall plant at the end of one year, and something over your head in about five years. It's also about this time that plants begin flowering,

    While minor pruning does not appear to harm kokiʻo, there should be little reason to do so because of its ideal natural growth form. Kokiʻo bark is soft and easily damaged by trimmers (weed-wackers). Therefore, we recommend using a trunk-protector or a perimeter of cinders around the tree's base to protect the trunk.

Pests and Diseases

    In addition to the soil problems described above, koki‘o is also attacked by a large variety of sap-sucking pests including aphids, leafhoppers, mealybugs, spider mites, and whiteflies. These pests are usually clustered at the stem-tips and can severely deform young leaves. Ants often farm these pests, so, they too need to be controlled. Chinese rose beetles may chew on koki‘o leaves, but the damage is usually less severe than on some other related native plants like ma‘o hau hele and ko‘oloa ‘ula. Rats too can be a problem, often eating kokiʻo seeds, even before they fall to the ground, or chewing at the base of the tree (which can be fatal). Refer to the Pests & Diseases page for ways to deal with each of these pests. 

Special Features and Information

General

    The large Mallow family, Malvaceae, contains about 4,200 species, with notables such as okra, cacao, durian, baobab, kenaf, and cotton [WikipediA;Malvaceae]. 

    Kokia is an endemic (to Hawai‘i) genus of four species. Three species are endangered: Kokia cookei, endemic to Molokaʻi; K. drynarioides, endemic to Hawaiʻi Island; and K. kauaiensis, endemic to Kauaʻi. One species endemic to Oʻahu, K. lanceolata, is now extinct; it was last seen in the 1880s [Wagner et al. 1990]. The decline of these four species has had an adverse effect on other native organisms, such as the Hawaiian honeycreepers, which utilized these trees for food [Pratt 2005].

Hawaiian Name

    Hau is a tree (Hibiscus tiliaceus), likely introduced to Hawai‘i by early Polynesians. Hau hele ʻula translates as "the red traveling hau" [Pukui & Elbert 1986].

Etymology

    Kokia is derived from kokiʻo, the Hawaiian name for these species. Botanists Otto & Isa Degener in Book 7 of Flora Hawaiiensis have this note regarding the name: "Lewton believes the vernacular name comes from ko-ki, 'The extremity; the end of the tree; a very high place. The native name of these trees, kokio, possibly relates to the habitat'" [Degener 1932-]. The species name, drynarioides, comes from Drynaria, a genus of ferns, and the Latin, -oides, meaning "resembling" [Gledhill 2008].