Clermontia kakeana flowers and leaves. Ripe (yellow) and unripe fruits (Photograph courtesy of Forest & Kim Starr, CC BY 3.0 US.). ʻŌhā planted under a large ʻiliahi with 'ukiʻuki and niʻaniʻau. (Header photograph courtesy of G.D. Carr©.) 

Growth Requirements

General

    It should be said at the outset that even though we have grown ʻōhā wai to sizable shrubs, neither of us has grown it to the flowering stage as yet. This is what we know at this point about Clermontia kakeana. ʻŌhā wai can be a bit more challenging to grow than some other easier-to-grow lobelioides or Campanulaceae (e.g., Cyanea, Delissea, Lobelia). One of the reasons is that it is very susceptible to spider mites, especially in hotter summer months, and it is often an ongoing battle to grow and maintain plants under such attacks. Add to this are alien slugs and snails, especially in the rainy months or naturally wetter locations, which will destroy your plant in a short time. The reality is that in lower elevation gardens, without controls for these major pests, it is likely a matter of time before your plant will not survive at all! So, unless you are vigilant and willing to treat the plant with miticides and against invasive alien mollusks, this may not be the plant for you. Now, that said, if you are willing to take on the challenge and use your time and effort to grow this wonderful species, you will be rewarded with a unique and beautiful addition to your native garden. 

    For containers, ʻōhā wai appreciate a rich potting mix of equal parts of peat, perlite, and black cinder. I (Eickhoff) also add "native compost" containing mycorrhizal fungi, which helps plants to take up water and nutrients and is beneficial to a plant’s resistance against pathogens [Koko 2021]. See Soils & Media Native Soils. Sufficient water to remain moist and a monthly feeding with an organic or appropriate fertilizer are essential for good health, proper growth, flowering and fruiting. See Fertilizers for suggestions. The naturally large, but rather thin, leaves are designed for semi-shaded conditions, but not for the strong afternoon sun. So, protect against the sun by growing under trees or shade cloth. For planting into the ground, consider carefully your planting site. It will need to be protected from the harsh afternoon sun, moist and free of alien snails and slugs. Outplanted ʻōhā wai will need constant monitoring for pests and enough watering, perhaps every day or every other day at least. The leaves and stems may droop for weeks or months after it has been planted in the ground. Drooping foliage is a sign that it is not receiving enough water. But do not worry! After giving it more water, it will perk up after a couple of hours with damage. Just do not allow the leaves to remain in this condition for more than a day, or cell damage begins to appear.

    If you choose to continue to grow ʻōhā wai in containers, it will eventually become root-bound. While it does not appear to resent cramped roots, it will, though, require more frequent watering, and nutrients from fertilizers may not reach all the roots since it is root-bound. A good indication that it needs repotting is when the leaves become droopy more often, even after watering. For these reasons, it is good to transplant to a larger container when roots are appearing from the drainage holes at the bottom. ʻŌhā wai transplants well without any noticeable growth differences. In fact, we have noticed over the years that carefully transplanting other lobelioides does not harm them either. 

Pests and Diseases

    The major threats are spider mites, slugs and snails, which have been addressed above. Refer to the Pests & Diseases page for treatments. 

Special Features and Information

General

    The twenty-four Clermontia species, collectively known as ʻōhā wai, are among the more common of the lobelioides (Campanulaceae), but also include some rare and endangered species. While nearly all the species are found as terrestrials, over half of the species also grow as epiphytes, that is, they grow on other plants, with one species always found as such. As epiphytes, they are often found on mossy trunks or branches of larger trees such as koa, ʻōhiʻa, and ʻōlapa (Cheirodendron trigynum) [Lammers 2005]. These plants produce two or more flowers on a typical inflorescence and are pollinated by honeycreepers (e.g., ʻiʻiwi, ʻakialoa) seeking nectar [Pratt 2005]. Yellow or orange berries are produced after flowering.

Hawaiian Name

    ʻŌhā wai, ōhā, and hāhā are all early Hawaiian names given to this species and many other native lobelioides. The name hāhā is also used for the two species of Brighamia, and specifically Clermontia arborecens in the same family, Campanulaceae, as well as the Kauaʻi name for ʻapeʻape (Gunnera kauaiensis) [Hawaiian Dictionaries], but applies to both endemic Gunnera spp. [Flora of the Hawaiian Islands].

Etymology

    The generic name Clermontia is named for M. le Marquis de Clermont-Tonnerre, Minister of the French Navy at the time of the Freycinet expedition (1817-1820) [Wagner et al. 1990]. The specific epithet kakeana is from Puʻu Kākea, a peak in the eastern Koʻolau Mountains, Oʻahu [Lammers 2005].