Annual vinca is one of the most reliable annuals for me when it gets hot in the summer. It does well in containers and tolerates the poor soil along the front of my retaining wall where I've planted them in mass in years past. This year I planted marigolds there and I'm just not loving them. I'd like to go back to annual vinca next summer BUT it seems like it's getting harder and harder to find them in 6 packs or 9 packs etc that are affordable. I'm wondering if I will have to wait until July to get flowers if I grow them from seed. Are they slow? I occasionally get volunteers that don't bloom until late June or July and I don't want to wait that long.

I don't have a greenhouse. I generally winter sow seeds but I'm not sure vinca can tolerate frost after germinating like some plants can. Any suggestions for named upright not trailing varieties that grow fast?

Should I forget it and grow whatever annuals I can buy cheap in 6 packs?