“Here then is a golden opportunity to build in upper Mānoa Valley, a vast botanical garden of native and introduced plants and at the same time carry through a project in water conservation that would prove of immense value to Honolulu.”

— Harold L. Arboretum (“Honolulu Can Have a Botanical Garden,” 1956)

The University of Hawaiʻi at Mānoa’s Harold L. Lyon Arboretum, the only university botanical garden in the U.S. and one of the largest located in a tropical rainforest, is celebrating its centennial year (1918–2018).

The arboretum kicked off the year’s planned activities with a Centennial Hoʻolauleʻa in August. Upcoming events include the Lyon Centennial Symposium, “Aʻohe Pau Ka ʻIke I Ka Hālau Hoʻokahi: Celebrating 100 Years of Research” on September 13–14, an Arbor Day tree giveaway on November 3, and the popular annual plant sale on November 17.

Lyon Arboretum Director Rakan Zahawi is excited for the future of Mānoa’s hidden gem. “Today, Lyon is at the forefront of conservation of native Hawaiian plants,” said Zahawi. “We’d like to showcase what we do and increase the visibility of the arboretum as we go forward.”

A long history of research

The nearly 200-acre tropical rainforest botanical garden has a long history of research. In 1918, the Hawaiian Sugar Planters’ Association ( HSPA ) purchased 124 acres in upper Mānoa Valley for research and restoration efforts of the watershed, which was damaged due to cattle grazing.

Harold Lyon was a plant pathologist hired by HSPA to lead the reforestation project. He concluded that the heavily damaged native forests could not recover on their own, and damaged watersheds could be restored with introduced plants. The planting project began in 1920 and was completed in 1945.

Lyon strongly believed that Hawaiʻi needed a botanical garden and saw this as an opportunity for the state. In 1953, the UH Board of Regents accepted the land from HSPA for a fee of $1 to use as a botanical garden with a mission of research, education and community service.

Lyon used his own money to fund the arboretum operations, and when he died in 1957 he left part of his estate in the trust to help fund the arboretum. The Board of Regents renamed the Mānoa Arboretum to the Harold L. Lyon Arboretum.

100 years later

Today the Lyon Arboretum continues to fulfill its mission. It welcomes 50,000 visitors annually to participate in classes, research projects, volunteer and other community activities, or to explore the extensive trails and plant collections.

Lyon Arboretum is one of two Level IV arboreta in Hawaiʻi accredited by Morton Arboretum’s ArbNet, the world’s only arboretum accreditation program. The UH Mānoa campus is the other arboretum that holds the distinction.

It boasts more than 5,000 tropical plant species from around the world. The Hawaiian rare plant program includes a micropropagation laboratory and seed conservation laboratory, which houses the largest collection of Native Hawaiian plant species. A new $2.5 million facility was constructed in 2017.

Related UH News Story: Critical piece of Native Hawaiian plant conservation completed, January 28, 2018

The arboretum is also spearheading the Rapid ʻŌhiʻa Death Seed Banking Initiative.

Related UH News Story: Lyon Arboretum leads Rapid ʻŌhiʻa Death Seed Banking Initiative, January 4, 2017

Extensive community outreach

The Lyon Arboretum offers ongoing activities that are available to the community. Their active volunteer program participate in activities including making lei, jams and jellies from flowers and fruit found on the property.

There are also classes such as Hawaiian lauhala weaving, a yoga and mindful hike and macrame workshops.

“It’s a beautiful place,” adds Zahawi. “Every time I’ve gone and walk the grounds, I’m struck by something new. It really is a showcase. A real landmark in terms of conservation efforts that the university does.”