Even before I started beekeeping, I noticed that anytime I had herbs flowering in the garden, the bees would always be all over them. Herbs like mint, rosemary, thyme, and oregano have tiny little flowers but the bees really seem to like them.
Right now, oregano is in bloom where the hive is located, and the girls are taking advantage of a close nectar source.
Urban Beekeeping in Austin, Texas 
These are gorgeous!