The Arboretum ("the Arb") at South Seattle College serves as an outdoor laboratory for landscape students and horticultural professionals. It houses groupings of ornamental and native plants, reflecting the interests of the home gardener and commercial landscaper. It serves the entire community as a natural retreat in the urban environment. The Arb was established in 1979, the result of a student petition to the College. The college supported efforts of students in the Landscape Horticulture Program to build and plant this five-acre urban garden site, located next to the West Duwamish Greenbelt. Currently, the Arb operates with one part-time management intern, one student intern and occasional volunteers. It is managed without chemicals, and therefore requires more labor to maintain. Volunteers who join the CoHort work alongside professional gardeners, and receive refreshments on CoHort work days, normally the 2nd Saturday of each month.