On Saturday, Oct. 1, UC Davis' arboretum will be crowded with home gardeners and horticulturists seeking unusual plants, herbs, shrubs, bulbs, vines and trees that will be available at this year's 20th annual plant faire. Hundreds of workers have spent thousands of hours propagating, watering and nurturing uncommon garden plants suited for the state's Central Valley. Expert gardeners will be at the faire to provide information on the more than 800 varieties of plants that will be on sale at the headquarters of the campus arboretum, near the intersection of La Rue Road and California Avenue. "The fall is an ideal time of the year to plant perennials and California natives in the Sacramento Valley, when temperatures are cooler, days are shorter and fall rains are near," says Ellen Zagory, arboretum nursery manager. For people without yards there are house plants, cacti and succulents. The plant sale supports the care and maintenance of the arboretum, one of the richest living museums in Northern California, with more than 2,000 varieties of trees and plants covering more than 150 acres along a two-mile stretch of Putah Creek.