Located at the corner of Sixth and Brannan, the SF Wholesale Flower Mart is where most local florists go during the wee hours of the morning to pick up fresh cut flowers, potted plants, blooming plants, and floral supplies. During those times, you need a special badge to enter, make purchases, and get special vendor deals.
If you have a florist friend, you can tag along with them, but if you don't, the San Francisco Flower Mart is open to the general public Mon thru Sat from 10:00am - 3:00pm. Even without the special discounts, this is still the best deal in town for fresh cut flowers. This is also a great place to pick up vases and other floral display supplies in bulk for cheap.