The University of California Cooperative Extension of El Dorado County will offer a master gardener class on container gardening from 9 a.m. to noon Saturday at the Bethell-Delfino Agriculture Building, 311 Fair Lane, Placerville. Additional classes include an introduction to "Ornamental and Culinary Herbs" on May 17 and "Ponds and Water Plants and Flowers" on May 31. For more information, call (530) 621-5512.