How far apart must I plant different varieties of basil?
If you aren't planning on collecting seed, you can plant different varieties in the same container. It is when you let the plants go to seed that pollen gets moved from one variety to another. If your intent is to collect seed, first know that hybrid plants don't come true from seed- will not be an exact replica - even if no cross-pollination occurs. To prevent cross-pollination, Univ. of Florida recommends varieties should be 150 feet apart. http://gardeningsolutions.ifas.ufl.edu/plants/edibles/vegetables/basil.html