Thomas Leo Ogren holds a Master of Science in Agriculture, with an emphasis on horticulture, urban forests, and plant flowering systems and the connections between landscape plant materials and allergy.
Tom started researching allergy-free gardening twenty-five years ago, because his wife, his mother and his sisters all suffered from hay fever and asthma. He is the creator of the Ogren Plant Allergy Scale (OPALS^TM), the first and only numerical plant-allergy ranking system in existence, which is being used by the USDA to develop allergy rankings for all major U.S. urban areas.
For twelve years, Tom taught landscape gardening in a California Youth Authority maximum-security prison, and he has also worked with the University of California Cooperative Extension, to establish community gardens in the Los Angeles inner city. He has been the co-owner of a family nursery in the Midwest, where he hosted the popular radio call-in gardening show, "Tom Ogren's Wild World of Plants." He writes for Garden Design, California Landscaping, The New Scientist, Alternative Medicine, American Rose, Organic Gardening, Conscious Choice, Awareness, Environmental Building News, Environmental News Network, Pacific Coast Nurseryman, Pioneer Thinking, Exotic Gardening, All Allergy, Foods Matter, and many other fine magazines and webzines.
Tom does consulting for allergists, hospitals, school districts, nurseries, landscape architects and designers, for the Public Health Department of the State of California, and for individuals. Each year he does extensive traveling, looking for new pollen-free cultivars, and he gives a great many talks and lectures. In the past few years he has lectured in several dozen states in the US, on the Isle of Guernsey off the coast of France, in England, and on both the north and south islands of New Zealand.
Many articles about Tom's revolutionary work on plants and allergies have been featured on radio, TV, magazines and newspapers worldwide. He is currently working on a new book, called The Highway Naturalist. Recently, too, he's been writing music…for a taste of some of his music, please visit the Myspace page http://www.myspace.com/sweetbigtime and while you're there, do get a listen to his new song, Sitting in My Own Backyard.

Tom lives with his family in San Luis Obispo, California.