Self-sowing annuals can't be beat, and can be sown directly... even now in the winter. I only have California poppies (and a scattering of a small number of others) but they are great. Used to have calendula, until their turf was eventually taken over by perennials (mainly self-seeded).
Oh, as I think about it, I guess I have others too... my neighbor's tidy tips and bachelor buttons which the swirling winds have brought into various parts of the yard. The tidy tips have rather a short season, very colourful in bloom though.
