Native Hawaiian Garden (7722)

Kolomona (Senna gaudichaudii) – Plants without stories

I firmly believe State and Federal agencies will have few successes in protecting and preserving Hawai‘i’s unique flora and fauna without direct public involvement. This is why I spend so much time engaging everyday non-biologists in native plant recovery projects. Of course, convincing the general public that our endemic plants and animals are precious and should be saved is often a challenge. This task is made easier when the plant has an interesting story I can share. The story may be in the meaning of its Hawaiian name, what Hawaiians use the plant for, some unique morphological, physiological or ecological characteristic of the plant, or even a personal story of my relationship with the plant. Unfortunately, not all of Hawai‘i’s plants have stories (that I know). Kolomona is an example of a plant without a real story (but see *** below). It is likely ancient Hawaiians used the white and green flower for lei but Hawaiians used many native flowers in lei. Maybe, they had some significant use for the beanlike pods or wood that we don’t know about. There is nothing remarkable about kolomona biology or ecology; it’s a native dryland shrub. The plant is indigenous, so I cannot convincingly argue that if we don’t save kolomona here in Hawai‘i it will disappear from the planet. And, I will not even try to use the tired sell, “Perhaps, someday scientists will discover a chemical in kolomona that will cure cancer or diabetes …”

For native Hawaiian plants like kolomona and many others, I’m forced to use a more philosophical argument to, just maybe, convince a workday volunteer that she or he should spend a Saturday morning getting hot, sweaty, and dirty helping this plant survive another day. My “story” goes to the very heart of human inquiry, the BIG question, “Why am I here? What is my purpose?” While most of us by the time we are adults have answered this question either via religion, philosophy, self-reflection or some other way, none of us know with absolute certainty the answer to our existence. Still, I will argue that each of us, all seven billion of us, believe we have a reason – a right to life. So, does that right to life only hold true for us? No, I don’t think so. If we can justify our own existence without knowing (for certain) our purpose, then, it is only logical, only fair, that we extend that right to life to all living things on Earth, even an innocuous Hawaiian shrub without a story.

( *** Mathew Manakō Tanaka, a Hawaiian Language student, dismayed after reading I had no story for kolomona, decided to do some research of his own. Searching through a database of old Hawaiian newspapers, Mathew found several references to kolomona flowers being used in lei. He also found an interesting reference to post-contact Hawaiians making ‘ōpelu fishing nets from kolomona rather than the traditional ‘ūlei. Thanks Manakō.)

Habitat & Appearance: Kolomona is sparingly found on all the main Hawaiian Islands except Ni‘ihau. It is indigenous to Hawai‘i, also occurring in Fiji, Tahiti, and other Pacific Basin islands. Nearly all the wild kolomona I’ve seen were small short shrubs in open dry shrubland or forest with the exception of one small tree (maybe, 7-8 feet tall) I came across in a mesic O‘ahu forest. Kolomona has dull green compound leaves similar but not identical to those of uhiuhi (simple pinnate versus bipinnate). Unlike its more showy introduced relatives with bright yellow flowers, kolomona has greenish-white flowers that tend to blend in with its foliage. (Supposedly, some kolomona flowers have a red tinge but I’ve yet to see one.)

Kolomona seedpods (Photograph courtesy of Forest & Kim Starr CC BY 2.0). Kolomona seedlings. Overwatered seedlings. Flowers and leaves.

Kolomona in Hawaiian Culture: See above.

Collecting Seeds: Wild kolomona usually flower just once during the wetter winter months, however, cultivated plants can flower repeatedly throughout the year. Seedpods develop and ripen quickly, becoming dry, dark brown to black, and often remain attached to the plant long after maturing. Unfortunately, seedpod borers (maybe the same ones that attack our native koa?) often destroy much of the seed within the pods. To prevent this from happening, secure a fine mesh net bag (see photograph on hao webpage) early around the still young small green pods. Seeds stored in a refrigerator remain viable for at least ten years.

Growing from Seed: Soak kolomona seed overnight before scarring (with sandpaper or a nail-clipper) and sowing. Within a week, the seeds will sprout. (I use Method Two for this easy-to-sprout plant.) Seedlings grow pretty quickly, even quicker with a bit of controlled-release fertilizer. In three to six months, your kolomona should be 6-10 inches tall and ready for planting in the garden. The one serious mistake I’ve made with kolomona in the nursery is too frequent watering. Kolomona seedlings DO NOT like getting their leaves wet (often). My problem was I use an automated sprinkler to water most of my plants once a day in the shadehouse. This was too much for the tiny kolomona seedlings. Their leaves started to rot (see photograph) and many of them died until I realized I needed to handwater just the potting media of these keiki. Aphids, whiteflies and other sap-sucking insects sometimes attack kolomona seedlings in the nursery. Eliminate these pests with horticultural oil, a systemic insecticide, or both.

Growing from Cuttings: I have never tried to propagate kolomona from cuttings.

Growth in the Garden: Planting your kolomona in a garden site that receives the maximum amount of full sun is best. This shrub grows and matures quickly with little or no watering; expect to see flowers and fruits within a year of planting. While kolomona never gets very big and matures quickly, it, nonetheless, has a significant lifespan of at least ten years.

Diseases & Pests: In the garden, aphids, mealybugs, scale insects and thrips occasionally infest kolomona. Rarely, these pests have killed a young kolomona I just planted out. In most cases, natural predators (e.g., lacewings, ladybird beetles) eliminated the pests without my intervention. Of course, you can be more proactive than me with repeated sprayings of insecticidal soap or horticultural oil. Black twig borers sometimes attack kolomona, but rarely with fatal consequences. See Enemies in the Garden on how to combat the black twig borer.

Ā ā Ē ē Ī ī Ō ō Ū ū