The horticulture department is located in a busy complex consisting of a greenhouse, two shade houses, and buildings that house tools, vehicles and heavy earth-moving equipment. An area is set aside to turn animal manure into compost. Inside the conservation greenhouse, various plants are grown year-round. During the winter, the greenhouse is filled with tubes of sage, grown for endangered pygmy rabbits. In the spring, Kincaid's lupine is grown for the Fender's blue butterfly. The shade houses are full of western blue violets (Viola aduncas), destined to nourish pupae of the Oregon silverspot butterfly. New shade houses are being added to meet the growing demands of our butterfly conservation program.

Good gardening practices help make the zoo an ideal habitat for the animals that live here on exhibit, as well as native wildlife such as hummingbirds and butterflies. If you think of the entire zoo as a theater, then horticulture sets the stage upon which the animals appear.