I have friends in the East Bay who run a very succesful organic catering company called Back to Earth . If you check out their website and give them a call I“m sure they can recommend the names of florists they work with that specialize in organic and/or local flowers. Another option, which would be a little more do-it-yourself, would be to go the farmers’ market and ask the local vendors there who are selling flowers if they could provide flowers for your wedding. I don’t know if the Berkeley farmers’ market has locally-grown flowers, but the Ferry Building market and the Alemany market (Saturdays, take 101 to 280 and get off at the first exit, the outdoor market is right there) both have local vendors who sell flowers and I“m sure would be happy to make a deal providing you with lots of local in-season flowers in July. It would also be MUCH cheaper. I know the Alemany bouquets sell for around $5 each and they are really lovely. Probably even cheaper if you bought in bulk.