And, ah, yes: ‘companion planting’; a topic laced with more folklore, hopefulness, bad information and just plain hype than just about any other in the gardening world. It’s said to have begun just as the world was going from BC to AD, when the oft-quoted Pliny the Elder wrote that the (highly toxic) plant rue was a “very friendly” companion to figs. – Mike McGrath, “The Truth About Companion Planting”
McGrath’s is not an uncommon position. Companion planting is a messy topic than needn’t be messy. It’s messy first because a lot of pseudo-scientific nonsense has been published on the topic, and second because even within the area of what makes sense, there’s a wide variety of approaches and techniques.
The basic idea behind companion planting is both simple and sensible: many plants grow better near some companions than they do near others or when alone. The devil is, as usual, in the details, in this case in the precise definition. (more…)