Native Hawaiian plants have been growing here for thousands of years and are well adapted to the climatic conditions of their island home. Including them in your garden offers an opportunity to grow a plant with connections to Hawaiian culture. Native plants also attract native insects and pollinators. And, they are lovely.
One of my personal favorites is the silver-leaved endemic shrub kulu’i. Originally found here in drylowlands or mesic forests, the plant is a true Hawaiian treasure. Slightly different varieties can be found on different islands. The Oahu variety, Nototrichium sandwicense, has highly reflective, silver-green leaves and an upright growth habit. The Kauai species, Nototrichium divaricatum, is more prostrate but still has the characteristic gray-green leaves. A Big Island variety of Nototrichium sandwicense has slightly greener leaves and is often used as a hedging plant. Most other characteristics of kulu’i plants are quite similar.
Today this attractive native is gaining popularity as a result of landscape architects’ decisions to include more native plants in their designs. It is also an excellent choice for sunny, dry locations even near the ocean. Kulu’i can also tolerate moderately windy locations up to 2,000 feet in elevation.
Most of the kulu’i varieties known as Nototrichium sandwicense are members of the large Amaranth family and share some of the mystical characteristics of the family. The writings of Scott Cunningham link amaranth plants closely to the spirit world. Kulu’i plantings are reported to attract spirits and have been the site of nighttime ghostly gatherings according to legend.
Kulu’i plants have been used throughout Hawaiian history as part of fiery shows. The wood burns brightly and crackles as it burns making it an ancient equivalent of a fireworks display. It is also used as a dramatic accompaniment for nighttime cliff divers.
The outstanding characteristic of kulu’i plants, is their soft, tomentose, leaves, which can be up to five inches long. Their silvery coloration is noticeably different from most other landscape plants. This hearty little shrub is a visual delight when a light breeze catches the leaves. It then appears to be a multitude of tiny mirrors scattering silvery light over the landscape.
The silver appearance of the leaves also makes kulu’i useful in lei and flower arrangements. Twisted young branches are sometimes used to replace or accompany maile vines in a lei. The woody stems of kulu’i can be used as an attractive addition to dried as well as live floral arrangements.
Kulu’i is a low maintenance, xeriscape plant that requires little care beyond pruning to maintain the desired height and shape and to keep the branches from getting leggy. In the right place, kulu’i shrubs can grow to twelve feet but can be used as a reliable hedging plant, maintained at about six feet tall. A healthy kulu’i plant will take on a rounded shape at maturity and can spread up to four feet in each direction from the base.
The gray-green coloration of the leaves is a characteristic common to drought tolerant plants. Once established, kulu’i can tolerate very dry conditions, like those often found during the drier months of a Kona winter or in dryland forest areas throughout the islands.
Though kulu’i does produce a small insignificant flower, the fruiting body is more noticeable. The seeds are clustered on the light-colored spikes that form at the end of branches which adds to the silvery appearance of the shrub. Though the seeds are viable when dried, kulu’i is more easily propagated from cuttings.
For good results, take semi-hardwood cuttings about four inches long from non-fruiting branches. Remove most of the leaves and dip the base into a rooting compound. A medium of one-half vermiculite and one-half perlite works well. This mix holds some moisture but drains well to keep the mix from getting soggy. Keep the cuttings in a shady area until they are fully rooted, which can take up to three months. Once the cutting seems fully rooted and begins to put out new leaves you can move it to a larger pot of soil that drains well. It is advised to leave the new plant in the pot for six months or more before planting out into the garden. “Harden” the new plant by placing it in its new location for a week or two before installing it in your garden.
Kulu’i plants can also continue to thrive in pots. They will do well for many years, in a sunny location in soil that drains well and is allowed to dry out between waterings.
Fertilizing lightly a few times a year is adequate for kulu’i. Too much water or fertilizer can make the plant overly succulent and highly attractive to insects or diseases. When kulu’i plants are healthy, insects and diseases are rare. The occasional attacks by mealy bugs or aphids can be easily treated with a soap and oil spray.
Kulu’i plants are available at many local nurseries. You can usually find most varieties of kulu’i and other Hawaiian native plants at Amy Greenwell Ethnobotanical Garden in Captain Cook.
Gardening Events
•Saturday:
“Work Day at Amy Greenwell Garden” from 9 a.m. to 12:30 p.m. Meet at the Garden Visitor Center across from the Manago Hotel in Captain Cook. Come with a mask and prepared to practice social distancing. Volunteers can help with garden maintenance and are invited to bring a brown-bag lunch. Water and snacks provided. Visit the website
•Friday, June 9: “Chainsaw and Mist Blower Maintenance” from 9 to 11 a.m. at the UH CTAHR Extension Office in Kainaliu at 79-7381 Mamalahoa Hwy. Tony Savarese with All Tool will discuss routine care of equipment, he’ll demonstrate sharpening a chain and answer questions. You need to reserve a ticket here: https://www.eventbrite.com/e/chainsaw-and-mist-blower-maintenance-and-troubleshooting-tickets-634274511137 Sponsored by Kona Coffee Farmers Association. Free to members, $15 for non-members, pay at the door. Seating is limited so please RSVP.
•Tuesday, June 13: “Go Farm Hawaii Webinar” at 5:30 p.m. to discuss new cohort starting June 2023. Open to those looking to improve farming production and agribusiness skills. Details on website www.gofarmhawaii.org
•Save the date: June 15 – 17:
“Hawaii Coffee Association’s 2023 Annual Conference &Cupping Competition.” A live event at the Kauai Beach Resort &Spa. For more information go to https://www.hawaiicoffeeassoc.org/Events
•Saturday, July 1:
“55 TH Annual Hawaii Macadamia Nut Association Meeting &Conference” 8:30 a.m. to 2 p.m. at Nani Mau Gardens in Hilo. $50 fee include conference and lunch. More information and registration are at www.hawaiimacnut.org .
Farmer Direct Markets
(check websites for the latest hours and online markets)
•Wednesday:
“Ho’oulu Farmers Market”
9 a.m. to 2 p.m. at Sheraton Kona Resort &Spa at Keauhou Bay
•Saturday:
“Keauhou Farmers Market”
8 a.m. to noon at Keauhou Shopping Center. Information on their online market: keauhoufarmersmarket.com/onlinemarket
“Kamuela Farmer’s Market”
7:30 a.m. to noon at Pukalani Stables
“Waimea Town Market”
7:30 a.m. to noon at the Parker School in central Waimea
“Waimea Homestead Farmers Market”
7:30 a.m. to noon at the Waimea middle and elementary school playground
•Sunday:
“Pure Kona Green Market”
9 a.m. – 2 p.m. at Amy Greenwell Garden in Captain Cook
“Hamakua Harvest” 9 a.m. to 2 p.m. at Hwy 19 and Mamane Street in Honoka’a
Plant Advice Lines
Anytime: konamg@hawaii.edu
Tuesdays &Thursdays: 9 a.m. to noon at UH-CES in Kainaliu – 322-4893 or walk in
Mon., Tues. &Fri: 9 a.m. to noon at UH CES at Komohana in Hilo 981-5199 or himga@hawaii.edu
Diana Duff is a plant adviser, educator and consultant living part time in Kailua-Kona.