Hello Greenthumb -

All of the varieties of annuals you have listed have self - sowed for me, It doesn't really matter what variety - they all will self sow, The Balsam tends to produce single flowers after several seasons of self sowing, and snaps will become less showy than their parents. I have a hillside that is covered with blue batchelor's buttons that have resown themselves for more than 10 years. There is Portulaca - moss rose that grows and flowers here beautifully in the gravel between patio stones that seeded themselves there from the garden. Bells of Ireland is at its best when it self sows.
You have to give these self sowing annuals real good to ideal conditions (well drained fertile soil, little competition with weeds) and a full day of sun for them to return from self sown seeds. Good luck!

I've seen Calendula, Bachelor's Buttons, cosmos and snapdragons reseed themselves. They did so even more readily when I lived in WI@ zone 5.

At my grandma's garden there seem to be cosmos that always find a way sprout. Bachelor's Buttons act as a perennial.

Other regulars:

- California poppies
- candytuft
- oregano (perennial and volunteers)
----------
Now for some unusual ones I've seen:
- Lobelia erinus (1 time so far)
- Petunias (several locations)
- impatiens W.

I mean seriously how the heck did those seeds survive?! The plants themselves are only hardy to zone 10 or 11. I'm pretty sure the seeds had to have been exposed to below freezing.

This post was edited by fieldofflowers on Wed, Aug 6, 14 at 7:31