Native Hawaiian Garden (7722) - ‘Akoko (‘Ewa Plains)

‘Ewa Plains ‘Akoko (Euphorbia skottsbergii var. kalaeloana) … making a last stand.

It always amazes me when I find a plant that is so easy to propagate and grow in the garden but is critically endangered in the wild. Such is the case with the ‘Ewa Plains ‘akoko. In 1979, Winona Char and N. Balakrishaan reported that there were approximately 4,388 ‘akoko in six locations stretching from the proposed deep-draft harbor and West Beach Resort area (neither had been constructed yet) to the far east end of the Naval Air Station at Barbers Point. They suspected there were additional plants farther east into ‘Ewa and ‘Ewa Beach but these areas were outside their contracted survey area. While efforts were made by the State of Hawai‘i and the US Army Corps of Engineers to preserve the nearly 2,500 ‘akoko growing in the deep-draft harbor area, today, the plant can no longer be seen there. Likewise, the approximately 1,300 ‘akoko seen in 1979 in the West Beach Resort area are no more, all killed by a poorly-researched and managed translocation. According to Char and Balakrishaan, approximately 100 ‘akoko in Campbell Industrial Park were killed by a bulldozer in 1979. Since then, the remaining ‘akoko in the Park have disappeared. In 1998, a survey by Whistler revealed only one ‘akoko in the northwest corner of the Naval Air Station where there had once been 18 in 1979. Finally, in 2004, in consultation with the US Fish & Wildlife Service, the US Navy conducted a cleanup operation of 23 acres in the northeast corner of the Station to remove lead and arsenic from the soil; the site was home to approximately 850 ‘akoko. While the Navy took great care to preserve as many ‘akoko as it could inside the cleanup area and established two new populations of ‘akoko outside the cleanup area, today, two of these three sites are nearly devoid of ‘akoko. The third site, I thought, was the last stronghold. With the help of volunteers, I was able to maintain this population of ‘akoko at about 800 adults. However, time has proved me wrong and in 2011, we lost approximately 80% of this supposedly stable population. Not to end on a sad note, in 2012, we started planting ‘akoko back into the Navy cleanup area, within small depressions that have accumulated new soil. These new plants have done amazing well, even beginning to produce new plants within the depressions and nearby. (This story has become too long to continue telling all here, but as of 2020, the largest existing population of ‘Ewa Plains ‘akoko is now within the Kalaeloa Heritage Park, started in 2013 with the help of many, many volunteers.)

Habitat & Appearance: As described above, this plant was once seen throughout the ‘Ewa Plains where the average annual rainfall is approximately 12 inches. It could be found either out in the open or under kiawe trees. It lives on calcareous substrate with sparse, fine soil, its taproot often penetrating deep within a crack or hole in the limestone. It does not persist anywhere where the alien buffelgrass grows thick. The ‘Ewa Plains ‘akoko is normally 2-4 feet tall and slender in appearance. The leaves are small, nearly round, and are shed during dry periods; you could easily mistake this ‘akoko for dead during the dry summer months. The very small flowers and exploding fruits are only seen after significant rains (or watering).

Flowers, ripe fruit, and leaves (Photograph courtesy of David Eickhoff CC BY 2.0). Germinating ‘akoko seeds in water. ‘Akoko seedlings. Me among a cluster of adult ‘akoko in 2005.

‘Akoko in Hawaiian Culture: There are 15 endemic species of ‘akoko found in Hawai‘i. All (to the best of my knowledge) share two traits recognized by Hawaiians. The first is the plant’s milky sap that Hawaiians of the past incorporated into a medicine given to new mothers who were having difficulty producing enough breast milk. Krauss (1993) also reports that the sap was used in paint for canoe hulls. The second trait is that damaged ‘akoko leaves turn red thus giving the appearance that the plant bleeds when it is injured; koko means blood. Alternatively, some believe the name ‘akoko is derived from the red bloodlike color of the fruits seen on some species. Pukui & Elbert (1986) state that Chamaesyce multiformis leaves and buds were chewed to treat debility.

Collecting Seeds: There are two ways to collect ripe ‘akoko seeds, the one-trip and the two-trips method. In the one-trip method, you wake up early in the morning and begin examining the fruits of your ‘akoko. Unripe fruits hang horizontally on their short stalk. Collect these and it’s very unlikely any of the seeds inside will germinate. Rather, you must wait for the ripe fruits to reveal themselves as they rise up and become erect and vertical on their stalk. Quickly collect the ripe fruit and place it in a bag before it explodes; this is the natural way the plant disperses its seeds. By noon all the ripe fruits for that day will have exploded and you can head home with your booty. In the two-trip method, look for a stem with many developing fruits, the more the better. Carefully, place a fine mesh bag over the stem and secure it so that nothing can get out. Return a few weeks later and remove the bag with the trapped seeds inside. ‘Ewa Plains ‘akoko seeds are short-lived at room temperature – perhaps, no more than a year. However, they can be stored for years (at least 15) in the refrigerator with little loss in viability.

Growing from Seed: It’s sometimes funny how you discover new things. In this case, I discovered an excellent way to germinate ‘akoko seed simply because I procrastinated. Several years ago, I was soaking some ‘akoko seeds in a shallow pan of water overnight in preparation for sowing them the next day. Well, I got lazy and left the seeds in the water for an extra day. To my surprise, after only 36 hours in the water, a few of the seeds began to germinate. With a pair of forceps, I carefully transferred each of the germinating seeds to its own small pot filled with clean media (transfer the seed to a dibble tube if you anticipate keeping them in the nursery for over six months). After refreshing the water, a day later more of the soaking seeds had germinated. After about ten days, replacing the water each day, only a few ‘akoko seeds remained. These, I finally discarded after waiting another week. Now, obviously, you don’t have to germinate ‘akoko seeds in the manner I’ve just described – they germinate just fine if you sow them after soaking them for a day. However, using this method will eliminate the need to transfer each seedling from a germination flat/container to growout pots. And, it’s just cool watching the new root emerge from the submerged seeds. Place the seedlings in full sun immediately to prevent spindly growth. They will grow fast and even faster if you fertilize them.

Growing from Cuttings: I have tried and tried to grow this species from cuttings without success. Others have grown other species of ‘akoko (e.g., Euphorbia celastroides) from cuttings, so, you can try your luck. Seedlings that pop up in the nursery or garden transplant really well. Even bare-root plants less than 12 inches will survive provided they spend their first couple of weeks under a mist in the nursery or are covered (using Method Three) in the garden or field.

Growth in the Garden: After 3-6 months in the nursery, you should have young plants 8-12 inches tall. Plant them into the garden at this time (You can even plant them out when they’re smaller, but you may need to protect them from insects, slugs, small mammals, etc.), and watch them really start to grow. Avoid the temptation to make them grow any faster by watering them. In fact, the best thing to do is not water them at all (except as part of the initial outplanting) unless you see the leaves severely wilted or drying out and falling off. In the wild, these ‘akoko naturally lose all their leaves and go dormant several times each year. After the plant is established in your garden, it’s your decision if you wish to mimic this natural behavior or circumvent it by watering – the plant will survive either way. (Just remind yourself when you water where this plant naturally grows – an area where the annual rainfall is about 12 inches.) By the time your ‘akoko is 15 inches tall, in less than a year, it will be flowering and producing lots of new seeds. The maximum height is about four feet. And, the maximum lifespan is about ten years. So, be certain to collect some seed in the first couple of years so you don’t get caught without replacement material.

Diseases & Pests: ‘Akoko seedlings and adults are susceptible to a variety of scale insects and mealybugs. The most commonly seen pest is the cottony cushion scale. Eliminate these pests with horticultural oil, a systemic insecticide or both; ladybugs work well too!

Ā ā Ē ē Ī ī Ō ō Ū ū