Here you can see four of the developmental stages of kokiʻo's spectacular flower: a well-developed flower bud with large basal bracts (Photograph courtesy of Eric White CC BY-NC-SA 3.0.); an open blossom with curved staminal column (Photograph courtesy of Kenneth R. Wood (NTBG) CC BY-NC 4.0.); in the header, the capsule-like fruits with bracts before they split open (Photograph courtesy of Kenneth R. Wood (NTBG) CC BY-NC 4.0.); and three mature fuzzy seeds; one reason for the vernacular name, Hawaiian cotton tree. The main veins of Kokia kauaiensis leaves are often, but not always, bright red (Photograph courtesy of Eric White CC BY-NC-SA 3.0.). A flowering kokiʻo on Kaua‘i (Photograph courtesy of Kenneth R. Wood (NTBG) CC BY-NC 4.0.).

Growth Requirements

General

     I (Koebele) am not sure why the State never approved the commercial sale of Kokia kauaiensis, since they did approve the sale of the equally endangered K. drynarioides. Based on my experiences growing the two species on O‘ahu (which, I admit, are limited), K. kauaiensis is the easier of the two to keep alive longterm in the ground on this Island. This may be because O‘ahu, like Kaua‘i, has more clay-dominant soils, while K. drynarioides is really only seen growing on lava/cinder-dominant substrate. (See my fuller discussion of this hypothesis on the Kokia drynarioides webpage.) It might also be, that because K. kauaiensis is adapted to mesic habitats, it is more forgiving of overwatering than K. drynairioides, which lives on dry lava flows or in dry forests. Hopefully, circumstances will change (maybe with your persistent requests to growers and State officials?), and this Kaua‘i cottontree will be more commonly cultivated on the older islands of Kaua‘i, O‘ahu, and Moloka‘i.

    As I stated above, I've only grown Kokia kauaiensis a few times. However, at least one of these efforts resulted in two small trees living past their tenth birthday. These two plants were planted at about 500 ft elevation in a dry forest restoration site near a normally dry stream bed. Unfortunately, I haven't visited these trees in many years (— it's complicated) so, I don't know if they are still alive. My other plantings elsewhere all died within a few years, probably because I planted all of them in dry non-irrigated sites, mistakenly thinking they were dry forest plants when, in fact, they naturally grow in mesic forests. (Shame on me for not doing my homework!)

    So, with all the history out of the way, here's what I recommend. The two kokiʻo mentioned above were planted in a site that was shielded from the sun for most of the morning but received full sunlight for the rest of the day. Other vigorous kokiʻo plantings I've seen on Kaua‘i were planted in a forested area such that they were shielded from early morning and late afternoon sunlight but received full sun between those times.

    While Kokia kauaiensis can tolerate surface-dry soil, I encourage you to keep your kokiʻo in soil that is constantly moist (but not wet). All the successful plantings I've seen were in either organic- or clay-dominant soils. However, these soils were also very rocky and the areas were sloped, thus providing excellent drainage. Similarly, K. kauaiensis can tolerate some heat and wind, but, because of the drying effects of each, I recommend planting your kokiʻo in a site where these are moderate to minimal. 

    My two ten-year-old kokiʻo were about seven feet (2.1 m) tall the last time I saw them. They also never flowered. I suspect kokiʻo grown in a wetter site (or in a naturally dry but irrigated place) would have grown considerably larger and have flowered at least once by that time. I never fertilized these or any of my other kokiʻo plantings. However, before planting out my kokiʻo, they did well in pots containing a 50:50 mix of sphagnum peat moss and black cinders. These potted plants were regularly fertilized with an inorganic foliar fertilizer every one to two months.

    Kokia kauaiensis seems to grow straighter — more tree-like — than K. drynarioides, when cultivated, which tends to be quite bushy (see the whole tree photograph on the Kokia drynarioides webpage). However, this may just be a consequence of the more shaded places I have seen it growing. In any case, I recommend against pruning your kokiʻo in any substantial way except to remove dead branches.  Kokiʻo bark is soft and easily damaged by trimmers (weed-wackers). Therefore, use a trunk-protector or a perimeter of cinders around the tree's base to protect the trunk.  

Pests and Diseases

    Similar to Kokia drynarioides, K. kauaiensis is 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. Kokiʻo bark is soft so you should regularly inspect the base of your tree for any damage caused by chewing insects, snails and slugs, or rats and mice. If you do see damage, identify the cause and take appropriate action quickly to prevent your plant from being girdled and dying. Refer to the Pests & Diseases page for ways to deal with each of the above-mentioned pests.

    As mentioned in Growth Requirements for Kokia drynarioides, K. kauaiensis may also be susceptible to the host of harmful alien microbes that have invaded Hawaiian soils. Therefore, if your planted koki‘o dies for no apparent reason, you might want to, next time, consider keeping it forever in a container.

Special Features and Information

General

    Koki‘o belong to the Mallow family (Malvaceae), which contains about 4,225 species within 243 genera. Family members include herbs, shrubs, and trees found worldwide, but most commonly in the tropics. Some of the more economically important species include: cotton (Gossypium spp.), cacao (Theobroma cacao), linden (Tilia spp.), durian (Durio spp.), Hibiscus, and okra (Abelmoschus esculentus) [Britannica;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

    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-].  

    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. (See Hawaiian Name above for the possible origin of kokiʻo.) The species name, kauaiensis, refers to the island of Kauaʻi, where this species is endemically found. The suffix -ensis was added to Kauaʻi to Latinize the name [Gledhill 2008].