It is commonly thought that Hawaiians named this species ‘akoko because of its blood-red (when ripe) fruits (capsules); koko is the word for "blood" in Hawaiian. Note that this mature wild plant among some rocks (Photograph courtesy of G.D. Carr ©) has considerably fewer leaves than this mature cultivated plant, almost certainly because it receives less water. The header is a closeup photograph of ‘akoko's flowers and nearly ripe fruits.

Growth Requirements

General

    While endangered, Euphorbia celastroides var. kaenana is one of the more commonly seen ‘akoko in cultivation, and is one of our favorite native plants because of how little care it requires. This underscores an important fact: Preservation need not be restricted to wild habitats but is also possible using cultivated landscapes.

    Use this ‘akoko as an accent, or, planted en masse 4 to 5 ft apart, as an informal hedge, but avoid pruning. It also does well in a container, provided the media drains water easily. 

    Euphorbia celastroides var. kaenana grows best in a site with full sunlight for all or most of the day, and will languish in a shaded location. It can be planted in well-draining coralline or lava/cinder soil or sand, and is tolerant of extreme heat, drought, strong winds, and salt spray. (It will also grow in clay-dominant soils provided you keep the soil dry 90-plus percent of the time.)

    Once established in the ground (in 1 to 2 months), water your ‘akoko sparingly or not at all, except for plants kept in a container, which will need regular but minimal watering. The amount of water your ‘akoko receives, either naturally via rain or from your watering will determine if it seasonally drops most of its leaves (as it does in the wild) or retains most of them year-round. Our preference is to mimic the natural cycle, but the choice is yours. However, do not overwater your ‘akoko because this can result in root or stem rot and death. 

    Euphorbia celastroides var. kaenana grows at a moderate pace in the ground and will begin flowering after one to two years. Once a plant starts flowering (when about two feet across), its growth slows, and it can be several years before it doubles its size. We have not fertilized our in-ground plants, and, therefore, cannot comment on whether or not fertilizer would speed their growth. For our ‘akoko in pots, we lightly fertilize with either a controlled-release balanced fertilizer every six months, or an organic or inorganic water-soluble fertilizer every few months.

    Because of the unpleasant odor of its flowers en masse, you might want to avoid planting ‘akoko near a window of your home. Prune only to remove dead branches and leaves, and avoid contact with the milky sticky sap that naturally oozes from wounds, since it may cause irritation or a rash. 

Pests and Diseases

    ʻAkoko are occasionally attacked by red spider mites, mealybugs, and scale insects. However, in our experience, this is rare, and, in the case of mature plants, the pests often disappeared over time, probably due to natural predators such as ladybird beetles or leaf shedding. ʻAkoko's milky sap may also deter many pests. Refer to the Pests & Diseases page for ways to deal with each of these pests. Persistent infestations are more likely if you have placed your ‘akoko in an unnatural environment, such as a heavily-shaded or over-watered site; consider moving your plant to a sunnier and drier location rather than resorting to continued chemical treatments. 

    Another ʻakoko pest is the giant African snail (Lissachatina fulica), which will come out of its hiding place at night and girdle the main stem of small newly-planted ‘akoko just above the ground; girdled, the young plant roots eventually starve to death and the plant dies. One method to prevent this from happening is to wrap the main stem in several layers of crinkled aluminum foil from the ground upward about ten inches. This will protect the vulnerable stem, and the snails seem to be unwilling to climb up the aluminum foil to get at the bark of the upper branches. Refer to the Pests & Diseases page for other ways to deal with snails. 

Special Features and Information

General

    Euphorbiaceae is a large family with about 7,500 species within 300 genera, found on all the continents except Antarctica, with the greatest diversity in the tropics. Some well-known non-native relatives of ʻakoko are the Castor oil plant (Ricinus communis), kukui (Aleurites moluccana), poinsettia (Euphorbia pulcherrima), cassava (Manihot esculenta), and the Pará rubber tree (Hevea brasiliensis) from which we get latex [WikipediA;Euphorbiaceae].

   There are 17 native species of ʻakoko (Euphorbia spp.) — all endemic to the Hawaiian Islands. Several ʻakoko are either vulnerable, rare or endangered, and two are considered extinct [Flora of the Hawaiian Islands]. They range in stature from very prostrate shrubs such as Euphorbia degeneri to tall trees like Euphorbia olowaluana, which can grow to nearly 30 feet — perhaps the tallest in the entire genus of about 2,000 species worldwide!

    Euphorbia celastroides is by far the most variable and widespread of all the Hawaiian Euphorbia. The unbent capsules (fruits) distinguish them from other ‘akoko species, except for E. herbstii and E. rockii, which have distinctively larger fruits.

Hawaiian Name

    ʻAkoko comes from the Hawaiian word for blood, koko. This is likely a reference to the red, or blood-colored, seed capsules that look like drops of blood on the plant [Krauss 1993, Neal 1965]. Alternatively, some believe the name comes from the observation that ‘akoko leaves, when damaged, often turn red, giving the appearance that the plant bleeds when it is injured.

Etymology

    Euphorbia is named after Euphorbos, a Greek physician of King Juba II of Numidia and Mauretania (52–50 BC – 23 AD), who married the daughter of Anthony and Cleopatra [WikipediA; Euphorbia]. The species name, celastroides, means "resembling Celastrus," a genus of shrubs and vines commonly known as staff vines, staff trees, or bittersweet [Brown 1956]. The variety name, kaenana, refers to Kaʻena Point on O‘ahu, where this variety is most common.