College of Tropical Agriculture and Human Resources logo

Hawaiian Native Plant Propagation Database

database logo

Gardenia brighamii
Alternative Botanical Names
None found.
Common Names
Potential or Traditional Uses
Lei (Flower or Seed)
Photo of Gardenia brighamii
A small tree up to 15 feet in the wild, Gardenia brighamii is generally not as tall in cultivation. The leaves are glossy green, 1 to 4 inches long and about half as wide. Young leaves often feel sticky. When not under cultivation, Gardenia brighamii have leaves only on the ends of the branches. In the garden, however, plants retain their foliage for much longer and are much fuller in appearance. Plants are long-lived in their natural habitat; one specimen has been documented for over 65 years. They are known to live for at least 15 years under cultivation.

The solitary white flowers occur at the ends of the branches. The flowers are tubular with 6 or 7 lobes, up to 1 inch long and have a fragrance similar to the common gardenia (Gardenia augustus). The flowers open in the late afternoon and last about a day. (Koob 1999; Mehrhoff 1993; Wagner 1990)

Habitat and Geographic Range
Gardenia brighamii is an endangered endemic species. It is a dry forest species that is thought to have once existed on all the main islands at elevations from 1100 to 1700 feet. Currently, only 15 to 19 individual plants are known to exist on Hawai'i, Lana'i, Maui, Moloka'i, and O'ahu. (Koob 1999; Wagner 1990)
Propagation by Seeds
Cultivated specimens of Gardenia brighamii flower more or less continuously. Wild populations on various island have different flowering and fruiting seasons. On O'ahu and Hawai'i, Gardenia brighamii blooms in the fall and winter, from October through December. The Maui, Moloka'i, and Lana'i populations bloom mostly in the spring, from March through May, with some additional flowering in December and July. John Obata has speculated that flowering may be triggered by rainfall. Gardenia brighamii is self-compatible and viable seed is produced by self-pollination.

The 1 to 1 1/2 inch oval to round fruit of Gardenia brighamii is green with whitish spots at maturity. The fruit inside is pale yellow containing straw-colored seeds less than 1/4 inch long. The seeds are difficult to remove from the fruit pulp. Stratton et al recommend ripening the seeds in a plastic bag. This softens the pulp making the seeds easier to clean. After ripening, the fruit flesh can be removed by either placing the fruits in a colander or strainer under running water or breaking up the fruit by hand in a bowl of water.

Best germination is obtained with fresh seeds. Koob recommends soaking the seeds overnight in water. Stratton's informants suggest 1 hour in tap water. Plant only the seeds that sink. Soaked seeds may germinate in about 4 to 5 weeks up to 3 months. Lilleeng-Rosenberger documents germination percentages ranging from 42% to 85% for soaked seed.

Seeds should be sown in a well drained mix such as 3 parts #2 perlite to 1 part Sunshine Mix #4. Lilleeng-Rosenberger's notes indicate that the seeds were sown on the surface of the moistened medium. Keep the medium moist until germination. The containers should be placed in a covered shaded area to control soil moisture and reduce damage from rain. Plants are flowering size in 3 years.

The germination rate is greatly reduced when the seeds are stored. If seeds must be stored, cleaned seeds should be air dried. They should be stored in a paper bag or envelope inside a airtight container with desiccant and kept in a cool place at about 25% relative humidity. (Koob 1999; Lilleeng-Rosenberger 1996; Mehrhoff 1993; Stratton 1998; Wagner 1990)

Propagation by Cuttings
Gardenia brighamii can be propagated from semi-hardwood cuttings. Cuttings from actively growing plants will root the most quickly. Best rooting is obtained using a medium strength rooting hormone (e.g. 0.1% IBA and 0.05% NAA) (Koob, email) and either a mist system or a humidity chamber. Rooting takes place in 1 to 6 months. (Koob 1999)
Propagation by Division
Not applicable.
Propagation by Air Layers
Gardenia brighamii has been propagated by air layers by U.S. Department of Fish and Wildlife personnel on Maui. (Mehrhoff 1993)
Propagation by Grafting
Gardenia brighamii can be propagated by grafting. (Stratton 1998)
Propagation by Tissue Culture
No information located to date.
Koob, Gregory A. 1999. A Hawaiian gardenia. Hawai'i Horticulture 2 (1):10-12.

Koob, Gregory A. "Rooting Hormone Question." Personal email. Posted 28 January 1999.

Lilleeng-Rosenberger, Kerin. 1996. Plant propagation notebook. Unpublished materials: National Tropical Botanical Garden.

Mehrhoff, Loyal. 1993. Recovery plan for the Hawaiian gardenia. Portland, Oregon: U.S. Fish and Wildlife Service.

Stratton, Lisa, Leslie Hudson, Nova Suenaga, and Barrie Morgan. 1998. Overview of Hawaiian dry forest propagation techniques. Newsletter of the Hawaiian Botanical Society 37 (2):13, 15-27.

Wagner, Warren L., Darrel R. Herbst, and S. H. Sohmer. 1990. Manual of the flowering plants of Hawai'i. 2 vols., Bishop Museum Special Publication 83. Honolulu: University of Hawaii Press and Bishop Museum Press. p. 1132-1133.

Search Database

Browse Database --
By Botanical Name
By Common Name

Other Native Hawaiian Plant Sites

Other Plant Propagation Sites

Database Bibliography

Database Home Page

Other CTAHR Databases

The image in this record is used with permission from Dr. Gerald Carr's Web site "Hawaiian Native Plants" at

Last updated:
26 August 2001

Please send comments and suggestions to