Native Hawaiian Garden (7722)

‘Ōhelo kai (Lycium sandwicense) – Superficial similarities

Several genera of native Hawaiian plants have different species that grow in separate habitats. Hawaiians often recognized this relatedness by giving the plants the same or similar names. For example, naupaka kahakai for the coastal Scaevola taccada and naupaka kuahiwi for the montane Scaevola gaudichaudiana. Other examples include: ‘akoko for over a dozen endemic Euphorbia species, and ‘ohe makai for the dry forest Polyscias sandwicensis and ‘ohe mauka for the wet forest Polyscias oahuensis. However, they sometimes made mistakes and gave only distantly related species the same or similar names based on superficial similarities. Such is the case with ‘ōhelo and ‘ōhelo kai. ‘Ōhelo is the Hawaiian name for three species of Vaccinium, native montane and alpine shrubs, all closely related to blueberries (in Ericaceae, the Heath family), but with red, orange, or yellow berries. In contrast, ‘ōhelo kai grows very near the ocean, hence the name addition kai, and is in Solanaceae (the Nightshade or Tomato family). Presumably, it was the similarly bright red fruits of ‘ōhelo and ‘ōhelo kai that led Hawaiians to give these two unrelated species similar names. (Lest you think I am shaming Hawaiians for this naming, be aware the name “blackfish” was originally given to killer whales by Native American fishermen, probably because killer whales are predominantly black. The term is still used today, even by scientists, to refer to some dolphins.)

Habitat & Appearance: ‘Ōhelo kai is a short or prostrate shrub indigenous to Rapa Nui (Easter Island), Rapa (Australs), Mangareva, Tonga, Pitcairn, Henderson, the Juan Fernandez Islands, and all the main islands of Hawai‘i. In Hawai‘i, it grows in dry coastal areas, often very close to the water’s edge. It has stiff light gray stems, narrow succulent leaves, and tiny white to pink to blue tubular four-petaled flowers. Ripe fruits are bright red and contain many tiny flat seeds. ‘Ōhelo kai is sometimes misidentified as the non-native pickleweed (Batis maritima) but can be distinguished from it by the distinctive solitary flower and red fruit.

Ripe fruit on stem with leaves. Crushed fruit with seeds. Seedlings. Mature plants in natural habitat on Maui. (Crushed fruit, natural habitat, and header flower photographs courtesy of Forest & Kim Starr CC BY 2.0).

‘Ōhelo kai in Hawaiian Culture: Hawaiians strung the fresh fruits of ‘ōhelo kai together with kauna‘oa into lei (McDonald and Weissich, 2003). Today (and perhaps in ancient times), the tiny tomato-like fruits are occasionally eaten.

Collecting Seeds: In the wild, ‘ōhelo kai fruits ripen and turn red in the fall and winter; in cultivation, flowering and fruiting may occur more often. Each fruit contains many tiny flat seeds. Separate the seeds from the fruit skin and pulp by splitting and crushing the berry in a container of water; the viable seeds will then sink to the bottom of the container. Allow the seeds to air dry, and then sow or store them. Seeds stored in a refrigerator remain viable for at least five years.

Growing from Seed: ‘Ōhelo kai grows along the coastline and has very tiny seeds, therefore, I germinate its seeds using the same method I use for hinahina kū kahakai seeds. Fill one or more 4-inch pots with beach sand and coral rubble, or with a 1:1:1: mix of peat moss, perlite, and black cinder. Sprinkle about 10 seeds on the surface of the media and GENTLY water them in. Place the pots in your nursery under 50% shadecloth and gently water them every day. After about a week, you should see the first tiny seedlings. More seeds will sprout for the next month or so. After the first seedlings appear, cut back on the watering and try not to get water directly on the seedlings’ leaves. This helps prevent water-loving fungi from killing the seedlings. After the seedlings have 6-10 leaves, carefully separate and repot each in its own container using the same potting mix. (I do this by submerging the pot in a container filled with tapwater; this helps to gently separate the intertwined roots of the seedlings.) The seedlings grow slowly at first, but in 3-6 months you should have a nice ‘ōhelo kai ready for your garden. You can speed things up a bit with fertilizer, but you will likely get a very unnatural-looking lanky ‘ōhelo kai that is more attractive to sap-sucking pests.

Growing from Cuttings: ‘Ōhelo kai can be propagated from cuttings using either Method One or Two. However, I have found this to be a less reliable method than growing new plants from seed. Cuttings can take months to root, and even longer to develop enough roots to make it safe to remove them from the clear container or mist chamber. Also, it has been my experience that seed-grown ‘ōhelo kai are more vigorous and resilient than cutting-grown plants in the garden (or restoration site).

Growth in the Garden: While ‘ōhelo kai will grow in clay soils, it does best in a container filled with coral rubble or black cinder with a small amount of peat moss. (Refer to my discussion on hinahina kū kahakai for a more complete explanation of why many native Hawaiian coastal plants do better in containers than in the ground.) Place your ‘ōhelo kai in the sunniest spot in your garden, and stop watering it every time you look at it. Of course, how sunny and dry that spot is, as well as the size of the container, will ultimately determine how often you need to water your plant. But, in general, once a day is way too much, and once a week is likely closer to the mark. ‘Ōhelo kai grows at a moderate pace and begins flowering and fruiting in about a year. Shaded, over-watered, or over-fertilized plants will develop lanky stems and papery leaves, and may even die, presumably from root diseases or pests.

In the wild, ‘ōhelo kai will drop most or all of its leaves, presumably because of drought. In the garden, I have mimicked this behavior by reducing my watering during the summer. I cannot say if this is helpful or harmful to the plant. However, I mention it so you don't despair if you come home from vacation to discover your ‘ōhelo kai leafless because your vaca-caretaker failed to water your plants. It likely is not dead and will recover if you resume watering.

Diseases & Pests: The usual assortment of sucking insects such as aphids, mealybugs, and whiteflies have occasionally infested my ‘ōhelo kai. I have also had broad mites attack my seedlings. However, unless the infestation became extensive, I did nothing and let natural predators like ladybird beetles (ladybugs) eliminate these pests over time. However, if you are worried or impatient, refer to Enemies in the Garden for methods to combat these pests.

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