In southern Ontario (zone 5-7) pansy flowers (or Viola's) are annuals. They have a habit of reseeding themselves and due to their cold hardiness, and can often make a reappearance the following year. It's not a guarantee though, so collecting pansy seeds is the safer route for repeated blooms year after year.

In southern Ontario chamomile often self seeds and will regrow the following year, but occasionally this won't be successful. Harvesting these tiny seeds is easy for guaranteed crops is easy.