Here's an information I have been seeking for a long time. Marché Paysan is an association in Romandie that gathers local producers. Their website (unfortunately only in French) provides a list of 77 stores / farms / markets where to purchase local products. You can type your address on that page to find the closest place to your home:

http://www.marchepaysan.ch/nos-producteurs/recherche-avancee/

Those local producers also propose trust-based self-service or self-picking (so much appreciated ). Some also provide home-delivery. Addresses by purchasing modes on that link:

http://www.marchepaysan.ch/nos-modes-de-vente/