Ehrenfried Pfeiffer (1899-1961) was born in Munich. He visited the USA several times in the 1930s, was awarded a doctorate for his groundbreaking Sensitive Crystallisation theory as a blood test for detecting cancer, and emigrated there in 1940. He pioneered biodynamic agriculture in the USA and helped found the Biodynamic Farming & Gardening Association. He died in Spring Valley, New York.

• ForewordIntroductionWeeds and What They Tell UsThe Battle Against WeedsThe Biological CombatWeedy WeedsMorning Glory and CoGoosefoot or ChenopodiaceaeParsleyPlantainPoisonous WeedsPleasant-looking WeedsMore Pleasant-looking WeedsSummer- and Fall-Flowering WeedsGood WeedsDynamic Plants

'The author was a pinoeer of biodynamic farming in the USA, and knows a thing or two about weeds ... For gardeners, there is also some good advice on weeds in compost heaps.'-- Network Review