From Old Wives’ Lore for Gardeners by Maureen & Bridget Boland; Copyright 1976 and published by Farrar, Straus and Giroux(New York)
In the short section, “Vegetables that make good neighbours,” the Boland sisters tell us that
[S]ince lists of which goes well with what make complicated reading (carrots, peas, beans, leeks and turnips all agree well, for instance, but of these only carrots should be planted near onions and garlic), a table would seem the simplest thing to follow.
And so they provide one. A more detailed table is here; an extensive list of “which goes well with what” is here.
Companion planting is a concept whose history dates back at least to the native Americans’ Three Sisters method of planting corn, beans and squash together in a mound. Interestingly, many “scientific experts” discount the whole idea because, you know, if you can’t prove something scientifically– or if your “expert” doesn’t know anything about what factors have been shown to have significant affects on growth and production– than that something just don’t exist.*
Ha. Beware “experts.” The “expert” to whom I refer apparently doesn’t know that the web site maintained by the division of the academic institution that grants him “expert” status generates 158 hits when you search for “companion planting.”
As you are planning your flower and vegetable gardens, just remember that some make better neighbors than others.
* A note about grammatical errors: some are intentional.