It has long been observed, by farmers, gardeners and botanists alike, that from time to time certain plants seem to affect certain other plants growing their near them—both favorably and unfavorably. By considering of these relationships, farmers and gardeners can improve the quality of food and flowers; reduce losses from pests and disease, drought, and frost; and enhance both satisfaction and pleasure in their work and financial profit.
Years of experimentation by Richard Gregg—and subsequently, Helen Philbrick and others—resulted in this unique reference book. It offers a detailed and comprehensive A-to-Z of plants and how they affect one another and their surrounding environment, including the soil, insects, and birds.
Helen Philbrick (1910–2011) worked with Richard Gregg and Evelyn Speiden Gregg to experiment with companion planting in the Gregg's own garden. She wrote extensively on the subject.
Richard Gregg was an early pioneer of companion planting. In the 1940s, he and Evelyn Speiden Gregg used their own garden to experiment with different plants.
Herbert Hans Koepf (1914–2007) was a hands-on farmer in Germany who went on to receive a PhD in agriculture, specializing in soil science. In 1962, after the death of Ehrenfried Pfeiffer, with whom Koepf had worked closely, he became director of Pfeiffer's biodynamic research laboratory in Spring Valley, New York. In 1970, he moved to Emerson College in the UK to run the annual biodynamic agriculture course until 1990. He lectured widely and was head of the Agriculture Section at the Goetheanum in Switzerland. His other books include Research in Biodynamic Agriculture: Methods and Results (1993).