The ONLA Garden was installed to honor the 100th anniversary of the Ohio Nursery and Landscape Association 1908–2008. The Ohio Nursery and Landscape Association (ONLA) is a non-profit trade association representing the interests of the state's nursery, garden center, and landscape industries. Many ONLA members are graduates of The Ohio State University and continue to support the arboretum through contributions and services.
The original ONLA Garden was located east of Howlett Hall but was removed when the Parker Food Science and Technology building was constructed. The new garden was dedicated on October 20, 2008, with members of the ONLA Board of Directors present. It received an honorary Landscape Award from the Association in 2009.
This new ONLA garden was designed by students in Landscape Design under Laura Burchfield and by Kathy Burkholder, then Chadwick Arboretum & Learning Gardens horticulturist. The landscape design students students also gained valuable hands-on experience by installing the woody plant material and the stone hardscapes.
The garden design features a pink, red, and white color scheme in the spring, transitioning into a white garden during summer and fall. Many of the plants featured in this garden are ONLA's selections of top landscape plants for Ohio. The site is shaded and stays consistently moist, allowing the use of astilbes and other shade-loving plant species that require moist to wet soils.