Nick E. Christians, PhD, is Professor of Horticulture at Iowa State University, Ames, Iowa, where he has taught courses and conducted research on turfgrass management and physiology since 1979. The author or coauthor of more than 880 papers, articles, book chapters, abstracts, and books including The Mathematics of Turfgrass Maintenance, Third Edition and Scotts Lawns: Your Guide to a Beautiful Yard, Christians has been the recipient of numerous honors, including the Outstanding Educator Award from the American Society of Horticultural Sciences and?the Iowa Legislative Teaching Excellence Award. He has been a Fellow of the American Society of Agronomy since 1995, and a Fellow of the Crop Science Society of America since 1996.