I save zinnia seeds over the Fall and Winter and plant zinnia beds the next Spring. This is one such bed.
I also grow some zinnias indoors during the Winter. I do get a few "volunteer" zinnias from seeds that fell onto the ground and survived the Winter, but that is only a few zinnias, because most zinnia seeds don't survive being on the ground during the Winter. That would be very poor storage conditions. I try to keep my saved zinnia seeds dry and cool.