Artemisia mauiensis produces panicles of small multi-floret flower heads that turn from yellow to brown as they age (yellow flowers photograph courtesy of Spencer Len Pote CC BY-NC 4.0; brown flowers photograph courtesy of Forest & Kim Starr CC BY 3.0 US). What makes this ʻāhinahina species particularly popular is its lacy silver foliage, thought to protect it from the damaging ultraviolet radiation it receives in its natural habitat. In the wild, A. mauiensis can get to be quite large (more wide than tall) with a gnarled trunk and branches (photograph of wild plants with Forest Starr courtesy of Forest & Kim Starr CC BY 2.0; photograph of aging trunk courtesy of Michael Finch CC BY-NC 4.0). At Auwahi and elsewhere on Maui is an ʻāhinahina previously classified as Artemisia mauiensis var. diffusa (photograph courtesy of Forest & Kim Starr CC BY 2.0) with leaves that look quite different from the silvery A. mauiensis growing farther upland. Many botanists think this is a hybrid between A. australis and A. mauiensis [Wagner et al. 1990].

In Hawai‘i, Artemisia mauiensis does best when planted in cool uplands, either in a semi-natural setting such as here outside the National Park Headquarters on the road up to the Haleakalā summit (photograph courtesy of Forest & Kim Starr CC BY 2.0) surrounded by other native montane plantings, or in a botanical garden in Kula, Maui, surrounded by colorful alien plants (photograph courtesy of Forest & Kim Starr CC BY 3.0 US). In the continental USA, a cultivar of A. mauiensis called 'Makana Silver' has been tested, given a 5-star rating (photograph courtesy of Penn State University (SEAREC) ©), and sold as a short-lived, fast-growing perennial or annual. It is popular in both public (photograph of United States Botanic Garden plant courtesy of Daderot Public Domain) and private gardens.

Growth Requirements

General 

    There are very few native Hawaiian plants that are more commonly grown outside the Hawaiian Islands than within. Artemisia mauiensis is one of these; another that comes to mind is ālula (Brighamia insignis). Perhaps one reason for this is because many homeowners outside Hawai‘i are accustomed to replanting a significant portion of their landscape each spring, while here in Hawai‘i we often assume/expect our gardens to last forever. In the continental USA, A. mauiensis is regarded as a fast-growing, short-lived perennial or annual, unable to survive the winter cold in most places. Here in Hawai‘i, just the reverse is true. For most of us, living in coastal or lowland areas under 1,000 ft (305 m) elevation, the summers are just too hot for A. mauiensis to live for more than a year or two. Only in the uplands (primarily on Maui) do you commonly see A. mauiensis in public and private landscapes survive for anything approaching its natural lifespan. Therefore, if you really love the look of this ʻāhinahina — and you live in a coastal or lowland area — be prepared to propagate or purchase a new plant every year or two.

    While Artemisia mauiensis is a shrub, because of its short lifespan in coastal and lowland areas, it's best displayed as a landscape accent or a container plant rather than using it to make a hedge or cover large areas (unless you are planting it in an upland site). A. mauiensis is adapted to intense sunlight in its natural habitat. However, this natural habitat is typically cool, and often foggy. Therefore, if planted in a frequently hot, low-humidity site, try to mitigate the drying air by misting your ʻāhinahina regularly, particularly during midday. Placing it in a location that only receives direct morning sunlight can also help.

    Wild Artemisia mauiensis sometimes experience drought (and survive). However, again, in a hot, low-humidity planting site, letting the soil or media surrounding your ʻāhinahina dry out is risky. Much safer is to plant your A. mauiensis on a mound of black cinders and regularly water the mound, trusting the porous cinders will prevent the plant's roots from becoming asphyxiated. In a pot, a media mix dominated by cinders is also the best choice. A. mauiensis can endure strong winds, but is intolerant of salt spray [Ethan Romanchak, per. comm.].

    Planted Artemisia mauiensis can grow quickly to two feet (61 cm) or more in width in less than a year, but then seem to slow their growth after they begin producing flowers. I (Koebele) never fertilized my in-the-ground plantings. My potted ʻāhinahina were given a granular controlled-release fertilizer every six months or so. Pruning is typically not necessary except to remove the occasional dead branch or the panicles of flowers (if you find them unsightly). However, I recommend letting any flowers fully develop and collecting and storing the cypselae (in your refrigerator) to propagate later replacement plants; you can also root ʻāhinahina stem cuttings. See Description above for a caution and advice on collecting seeds and rooting cuttings.

Pests and Diseases

    In my (Koebele) experience, most pests seem to avoid Artemisia mauiensis except for spittlebugs, maybe because of its aromatic leaves. Refer to the Pests & Diseases page for how to deal with this pest. 

    One potential pest not to be eliminated is Trupanea artemisiae, an endemic species of tephritid fruit fly (family Tephritidae) restricted to East Maui. It lays its eggs in the flower heads of native Hawaiian Artemisia species where the larvae presumably feed and mature [Starr & Starr 2012]. 

Special Features and Information

General

    Asteraceae is a very large family of mostly herbaceous plants with about 32,000 species within 1,900 genera with a subpolar to tropical worldwide distribution. Nearly all Asteraceae have what appears to be a single "daisy"-type flower that is actually a composite of several to many much smaller flowers called florets [WikipediA:Asteraceae]. There are about 250 native and non-native Asteraceae in Hawai‘i, with a little more than half being native [Flora of the Hawaiian Islands].

    There are about 500 species in the genus Artemisia worldwide. Well-known non-Hawaiian Artemisia species include: Absinth wormwood (Artemisia absinthium) used to infuse absinthe and other spirits; tarragon (A. dracunculus) used in food; several species of the ubiquitous sagebrush of the American West [WikipediA;Artemisia]; and the common mugwort (A. vulgaris) used in Korean cooking to flavor rice cakes, soups, and other dishes.

    There are three native species of Artemisia endemic to the Hawaiian Islands: A. australis found on all the main islands, A. kauaiensis found on Kauaʻi, and A. mauiensis found on Haleakalā, East Maui. Some botanists think an ʻāhinahina found on Maui and previously classified as Artemisia mauiensis var. diffusa represents a hybrid between A. australis and A. mauiensis (see photograph above) [Wagner et al. 1990]. 

Hawaiian Name

    ʻĀhinahina comes from ʻāhina, which means "gray, gray- or white-haired," referring to the plant's color. Hina also means "gray," with Hinahina meaning "very gray" [Pukui & Elbert 1986]. 

    The three native Hawaiian Artemisia species share the names ʻĀhinahina and/or Hinahina with some other native Hawaiian plants with silvery leaves. These include: the endemic silversword (Argyroxiphium sandwicense), endemic Geranium species, and the coastal hinahina kū kahakai (Heliotropium anomalum).

Etymology

    The genus name, Artemisia, is derived from Dioscorides’ name for Artemis (Diana), wife of Mausolus of Caria in Asia Minor [Gledhill 2008]. The species name, mauiensis, refers to the island of Maui, where this species is endemically found. The suffix -ensis was added to Maui to Latinize the name [Gledhill 2008].