This Link does not exist in your language, View in: English (en),
Or use Google Translate:  

attra.ncat.org/attra-pub/downl...pub/download.php

Certain plants can benefit others when planted in close proximity or used as botanical pesticides. This publication discusses the scientific and traditional basis for companion planting associations including trap cropping, weed suppression, physical-spatial interactions, and other relationships. It provides a companion planting chart for common herbs, vegetables, and flowers, as well as a listing of literature resources. An appendix provides information on the Three Sisters, a traditional Native American companion planting practice.