Gardeners tend to assume that any product or practice labeled as organic is automatically safe for humans and beneficial to the environment. And in many cases this is true. The problem, as Jeff Gillman points out in this fascinating, well-researched book, is that it is not universally true, and the exceptions can pose a significant threat to human health. To cite just two examples: animal manures are widely viewed as prime soil amendments. When properly treated, they are; but if they are insufficiently composted, they can be a source of harmful E. coli contamination. Even more dangerous, potentially, are organic insecticides like rotenone, which is every bit as toxic as the synthetic compounds it is meant to replace. Gillman's contention is that all gardening products and practices — organic and synthetic — need to be examined on a case-by-case basis to determine both whether they are safe and whether they accomplish the task for which they are intended. When gardeners are well informed about the precise nature and consequences of what they use and do in the garden, they are in a much better position to make responsible, effective choices. If you've ever wondered about the merits of a specific insecticide, herbicide, or fungicide, or debated whether practices such as planting cover crops or companion plants are worth the trouble, you'll find the answers you've sought in these pages, along with a clear, careful, and good-humored analysis of benefits and drawbacks. Ultimately, Gillman concludes, organic methods are preferable in most situations that gardeners are likely to encounter. After reading this eye-opening book, you will understand why, and why knowledge is the gardener's most important tool.