Answer: There are a couple of books that address the topic of companion planting: Carrots Love Tomatoes, by Louise Riotte, is the one I'm familiar with. Generally, though, so long as one crop doesn't shade another, or steal moisture and nutrients from another crop, then everything is hunky dory in the vegetable garden. Another common recommendation is to separate plant varieties and species that are in the same family and share succeptibility to the same pest and diseases. Mixing up the plants helps prevent epidemics and outbreaks. Crop rotations are also important. Rotation refers to planting crops in different places each year, since each crop/family takes certain nutrients from the soil, and others, like legumes, actually return nutrients to the soil. It also prevents the buildup of soil diseases and insects that prefer certain crops. Another excellent book that covers both crop rotation and companion planting, among a lot of other things is Gardening for Dummies, by Charlie Nardozzi. Hope this helps!
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