Hawaii’s Amy B.H. Greenwell Ethnobotanical Garden has long served as a living museum of the state’s indigenous plants.

Amy Beatrice Holdsworth Greenwell left the property to Bishop Museum as an educational and cultural resource when she died at the age of 53 in 1974. The Bishop Museum closed the garden to the public in January 2016 after putting the land up for sale.

Even though the garden, located in Captain Cook, remains closed to the public as it awaits a buyer, a dedicated team of volunteers come together every Saturday to work in the garden, West Hawaii Today reported.

The nonprofit Friends of Amy B.H. Greenwell Ethnobotanical Garden works with garden manager Peter Van Dyke to help preserve the garden and maintain its historic collection of indigenous plants.

“We sprang up to fill a need,” said Maile Melrose, the nonprofit’s president. “You know someone’s got to help. Someone’s got to help maintain the garden, find a new owner for the garden and look out for the future of the garden.

Jim Miller, a volunteer, has lived next to the garden for five years and said it was one of the reasons he bought his house. He led tours through the garden as a volunteer guide for the last two or three years it was open.

“The plants that are inside the garden are very rare,” he said. “A lot of them you won’t find in the wild anymore and only in a protected garden like this will you find some of these. People who have lived here all their lives haven’t seen some of these.”

Melrose said gardens like the Amy B.H. Greenwell Ethnobotanical Garden are “libraries of the future,” that can preserve in perpetuity trees and plants endemic to the state of Hawaii seen nowhere else and as “the last best reservoir of hope for plants.”