Growing Different Lavenders in Close Proximity

I'd like to grow about a dozen different varieties of lavender here in my high desert region of Arizona. It's an experiment really to see if a full-fledged lavender farm might be a possibility. Anyway, my question is, do I have to be careful that my different varieties aren't grown too closely together in order to keep their individual qualities pure? My beds of different varieties will be 3' apart from each other. And would 1 1/2 ft. apart from each other be enough room for each individual plant's health?

Intermingling of lavender varieties is only an issue if you intend to collect seeds and grow plants from them. Otherwise, there is no reason why you cannot grow different lavender varieties in beds that are near to each other as you have described.