One year my spring sown cosmos self-seeded and they bloomed again in the fall. Last year I sowed seed in late July and never got a thing.
I just ordered some from Wildseed Farms. The lady told me (for my area zone 7b anyway) that the best to sow now would be cosmos, zinnia, sunflower. I think the website says 60-90 days from when you sow you'll get blooms.
I forgot all about this post. Guess I need to toss some seed out there.
I sowed mine in Late May, they sprouted but are still no more than 4-5 inches tall :-/ I will be transplanting them into a raised bed to see if they take off soon. I'll post before and after pics if anyone wants them. I am *hoping* they'll give a nice fall show being so late O.o
After my last post I read 7 weeks from seed to bloom. I'm waiting until mid August to sow seed. Found a pic taken in mid October of a previous year's blooms, so that sounds about right.