Lyon Arboretum

Lyon Arboretum is a botanical garden with 193 acres of tropical plants and Hawaiian native species nestled in the rainforest climate of Oahu. The site includes garden paths, research facilities, and collections of rare island flora throughout its lush mountain setting.

The University of Hawaii established this scientific garden in 1918 to study tropical plants and conduct research on Hawaiian flora. The focus from the beginning was on preserving rare species and supporting botanical research in the islands.

The garden maintains collections of traditional Hawaiian medicinal plants that reflect how island communities have used the flora for healing and daily life. These living collections tell the story of how people and plants have grown together over generations.

The site is free to explore Monday through Friday and visitors can walk the paths on their own or join a guided tour. Early morning visits offer the best light and fewer crowds as you move through the garden paths.

The site houses over 5,000 plant species within its mountain microclimate, some so rare that they are grown only here in a specialized propagation facility. This ability to reproduce endangered plants makes the location a critical refuge for Hawaiian flora.