Closeup of ‘Ewa hinahina leaves and utricles (single-seeded fruits) (Photograph courtesy of Dan Clark CC BY-NC 2.0.). A comparison of a wild (with sky in background) and cultivated ‘Ewa hinahina.

Growth Requirements

General 

    Achyranthes splendens var. rotundata is a beautiful silvery easy-to-grow shrub that can provide an accent in the landscape, or, if planted en masse, create an informal (i.e., lightly pruned) hedge or screen; space the plants 3 to 4 feet apart. It can also be grown as a container plant.

    ‘Ewa hinahina grows best in a site with full sunlight for all or most of the day, but can also tolerate partial or light shade; it does poorly in heavily shaded areas. Water ‘Ewa hinahina infrequently but regularly and deeply (e.g., one long watering once a month as opposed to briefly watering daily). However, too much water can transform its beautiful silvery foliage to a pale green and can even kill it; ‘Ewa hinahina does poorly when kept in regions with high rainfall (i.e., more than 50 inches annually). ‘Ewa hinahina doesn't seem to be picky about soil or media type, except that it should drain water quickly; we have grown plants in lava/cinder, coralline (best), clay, and organic-dominant soils. ‘Ewa hinahina can endure high temperatures, severe drought, strong winds, and salt spray. 

    In cultivation, ‘Ewa hinahina grows and matures quickly, and you can expect a 1 to 2 foot (30 to 61 cm) tall plant producing flowers in less than a year. It can also regenerate from numerous fallen seeds; remove or pot these seedlings up to prevent crowding. ʻEwa hinahina in the ground rarely require fertilizer to keep them looking nice. However, for container plants, apply a slow-release fertilizer with micro-nutrients every six months, or spray the leaves every couple of months with a water-soluble organic or inorganic fertilizer diluted to ⅓ to ½ recommended strength.

    Cultivated ‘Ewa hinahina naturally grow into an attractive ball shape, so pruning is usually not needed except to remove the occasional dead branch. Always use a hand-pruner.

    While ‘Ewa hinahina, particularly those in the wild, can live longer than five years, our cultivated plants seem to "burn out" (i.e., senesce and die) around this age. (It seems the more you torture them [i.e., no watering and no fertilizer], the slower they grow and the longer they live.) Often, no-effort replacements will appear, sprouting from the numerous fallen seeds around the parent plant. However, to be safe, you should collect and store (in your refrigerator) a handful of ‘Ewa hinahina fruits so you can grow a new plant when needed; replacement plants can also be easily rooted from cut stems.

Pests and Diseases

   ‘Ewa hinahina is a target for mealybugs and scale insects. The mealybugs tend to cluster at the stem and flower tips. Or, they can infest the roots. Scale insects are usually seen on the stems and leaves. A particularly nasty scale insect is a brown, hard-shelled type (see photograph below) that reproduces rapidly and can kill your plant in just two weeks. Therefore, act quickly and prune away all the infested branches and then treat the remaining plant with horticultural oil and a systemic pesticide. ‘Ewa hinahina is also susceptible to root-knot nematodes and pathogenic fungi in the soil. Treating these successfully is difficult. Usually, the best 'cure' is to find another distant location in your landscape and try again. Finally, don’t confuse the short lifespan of ‘Ewa hinahina with a disease or pest problem. Refer to the Pests & Diseases page for treatments for mealybugs, scale insects, and root-knot nematodes. 

Mealybugs clustered on ‘Ewa hinahina stem tips and a deadly unidentified brown scale insect on stem and leaves.

Special Features and Information

General

    Amaranthaceae is a large plant family with about 2,000 species within 165 genera with a global distribution; most species are herbs or shrubs, and many are known to cause pollen allergies [WikipediA;Amaranthaceae]. 

    In addition to Achyranthes splendens, other native Hawaiian species in the family Amaranthaceae include: the extinct Achyranthes atollensis that once inhabited some of the Northwestern Hawaiian Islands; the also endangered Achyranthes mutica; three endemic species of kuluʻī (Achyranthes spp.); the likely extinct and little-known Amaranthus brownii from Nīhoa; the endangered endemic Amaranthus pakai; several endemic species of pāpala (Charpentiera spp.); and the endemic ʻāweoweo (Chenopodium oahuense).

Hawaiian Name

    There is no known ancient Hawaiian name, and hence no known ancient use(s) for this species. However, the following names are used today: ʻāhinahina, which is equivalent to āhina and hinahina and means "gray, gray- or white-haired" [Pukui & Elbert 1986], in addition to being the name of some native Hawaiian plants with silvery leaves such as the silversword (Argyroxiphium sandwicense) and Artemisia australis; and ʻEwa hinahina or hinahina o ʻEwa, which loosely translates as "the hinahina of the ‘Ewa" Plains of O‘ahu. We will use the modern name, ʻEwa hinahina, within this website, since this is the Hawaiian name we most commonly hear others using.

Etymology

    Achyranthes comes from the Greek words, achyron, meaning "chaff," and anthos, meaning "flower," referring to the chaff-like parts of the flower [Wagner et al. 1990]. The species name, splendens, translates as "striking" or "gleaming," referring to the brightness of the leaves. The variety name, rotundata, refers to the nearly round shape of the leaves [Gledhill 2008].