Nelda Matheny is president of HortScience, Inc. in Pleasanton CA, a horticultural consulting firm that she started in 1983. Nelda received B.S. and M.S. degrees in horticulture at the UC Davis. She is author of numerous books and peer-reviewed papers including, “The Landscape Coefficient Method” published by the California Dept. of Water Resources in "A Guide to Estimating Irrigation Water Needs of Landscape Plantings in California," which was the basis for California's water-efficient landscape regulation. Nelda has been involved in site evaluation, plant selection and landscape management using recycled water in California since the early 1980’s.