Kīpūkai's tiny flowers are initially all white but quickly develop a yellow throat that then turns dark purple as the flower ages (Photograph courtesy of Forest & Kim Starr CC BY 3.0; header photograph courtesy of Forest & Kim Starr CC BY 3.0 US.). Pollinated flowers develop into small swollen fruits that eventually break apart into four nutlets (Nearly-ripe fruit photograph courtesy of DouglasGoldman CC BY-SA 4.0.). Kīpūkai grows naturally in a wide range of habitats that include: periodically-flooded silty coastal flats (photograph courtesy of Forest & Kim Starr CC BY 3.0 US); sandy and rocky shorelines along with ‘ākulikuli (Sesuvium portulacastrum) (photograph of sandy habitat courtesy of Veronica McCleign CC BY-NC-SA 4.0; photograph of rocky habitat courtesy of Kenneth R. Wood (NTBG) CC BY-NC 4.0); and occasionally in dry urban areas (photograph courtesy of Alexander Wentworth CC BY 4.0).

Growth Requirements

General

    Kīpūkai reminds me (Koebele) a lot of alena (Borhavia repens). Both are native Hawaiian plants that are rarely planted but almost inevitably pop up in coastal landscapes, both natural and manmade. One can only guess why kīpūkai is not a more popular cultivated native plant here in Hawai‘i, but it may be because it often loses out in planting decisions to its more long-lived sister species, hinahina kū kahakai (Heliotropium anomalum). While many consider hinahina kū kahakai more attractive and useful than kīpūkai, both can be used as groundcovers (planted a couple of feet apart), particularly in coastal areas. Kīpūkai also has the advantages over hinahina kū kahakai of growing more quickly (i.e., covering an area quicker) and of naturally reseeding and replacing itself when it dies (something hinahina kū kahakai only rarely does when cultivated).

    Kīpūkai does best when planted in a site that receives full sunlight for all or most of the day and will languish if planted in heavy shade; shaded plants are less blue, more lanky, and flower less. It will grow in just about any type of soil (i.e., sandy, rocky, silty, organic, or even clay) provided the soil drains water quickly. However, it can also withstand brief periods of flooding (both fresh and saltwater), which may actually aid in its seed dispersion and germination. Natural rainfall is normally enough to keep kīpūkai alive and growing. If watered too frequently, kīpūkai tends to lose its attractive bluish tint, and can rot and die. Kīpūkai can tolerate extreme heat, drought, strong winds, and salt exposure (both in the soil and air).

    Kīpūkai grows quickly, and you should have a flowering plant one or more feet (30-plus cm) across in less than a year. In-the-ground plants normally do not require fertilizer. However, if you keep your kīpūkai in a container, it may benefit from infrequent (once or twice a year) applications of a single-digit balanced organic or inorganic fertilizer. Plantings far from the ocean may also benefit from being occasionally (i.e., once every month or so) sprayed with seawater which anecdotally seems to improve growth and appearance and deter pests. However, the salt accumulating in the soil can become a problem for less salt-tolerant plants (and difficult to flush away). Therefore, unless your kīpūkai is in a container, you may want to refrain from these seawater sprayings unless you have permanently designated an area in your landscape for salt-tolerant plants.

    Regular pruning of your kīpūkai's stem-tips will encourage branching and keep your plant(s) looking fuller and constantly producing new flowers. Consider using the cut stem-tips to produce new plants for your friends (see below).

    Unfortunately, kīpūkai are short-lived, lasting only a couple to a few years in cultivation. However, often you will have keiki (baby) kīpūkai sprout up around your plant before it dies, thus maintaining its presence in the landscape. If you don't see any kīpūkai keikis after about a year, begin collecting the tiny nutlets or stem-tip cuttings from your plant before it dies. These can be sprouted in a pot filled with sand (fairly easy) or rooted in 100% perlite (a bit harder), respectively.

Pests and Diseases

    Kīpūkai is infrequently attacked by sap-sucking pests (i.e., aphids, mealybugs, scale insects, and spider mites), particularly when grown in a suboptimal environment (e.g., too much shade or water). Snails and slugs can also acquire a taste for kīpūkai and eat its leaves and stems, sometimes consuming an entire plant in a single night! Refer to the Pests & Diseases page for ways to deal with each of these pests. Infrequent sprayings of seawater also seem to deter some of these pests. 

    Fungal rot, resulting in dieback or death, can be a problem if you overwater your kīpūkai. Avoid this by only watering when the surface soil is quite dry, and only planting in well-drained soil or in a container with a media mix that drains extremely well. 

Special Features and Information

General

    Heliotropiaceae is a family of approximately 450 species of small trees, lianas, shrubs, and herbs in three genera with a worldwide distribution; however, most species are found in the tropics and subtropics. Heliotropiaceae was considered a subfamily of Boraginaceae before 2016. [WikipediA;Heliotropiaceae]. 

    There are about 325 species of Heliotropium worldwide [WikipediA;Heliotropium], with two species native to the Hawaiian Islands, hinahina kū kahakai (H. anomalum) and kīpūkai (H. curassavicum), both coastal plants. Three non-native Heliotropiaceae are also found in Hawai‘i: the fourspike heliotrope (Euploca procumbens; syn. Heliotropium procumbens); the blue heliotrope (Heliotropium amplexicaule); and the tree heliotrope (Heliotropium arboreum; syn. Tournefortia arborea) [Flora of the Hawaiian Islands]. 

Hawaiian Name

    Kīpū can mean "to hold back or brace, as a canoe on a wave with a paddle," while kai is often used in reference to the sea [Pukui & Elbert 1986].

    Lau poʻopoʻohina and Poʻopoʻohina are names for this plant on Niʻihau, both referring to the color of the plant with hina meaning "gray or white-haired." Poʻo means "head" while poʻopoʻo means "sunken, as eyes of a sick person" or "indented, deep (as a bay penetrating the coastline." Lau means "leaf" [Pukui & Elbert 1986].

Etymology

    Heliotropium is derived from the Greek words helios, for "sun," and trope, meaning "turning," in reference to the erroneous belief that Heliotropium flowers turn to face the sun [WikipediA;Heliotropium]. Leaves and flowers of other genera that turn toward the sun are referred to as heliotropic. 

    The species name, curassavicum, is the Latinized name derived from Curaçao, an island in the West Indies [Gledhill 2008] where this species is considered native.