I can't say about the vinca, but I WSed my geraniums last month.
cAROL

Portulaca's are easily DSed. I don't know about Vinca's or Geranium's.

Vincas need really warm soil to germinate. 75-78 degrees F. And the baby seedlings don't like it much cooler. 70-72 degrees. I guess it wouldn't hurt to try, except the loss of the seeds if they don't do well. They may not grow very quickly. It's def. too early to do them though. I bought several varieties, as well as collected from last years plants. I'll be starting some inside and some outside.

Good Luck!

I have wsed perennial geraniums with some success. Don't know about the others. I am about to ws my hardy annuals this weekend and will probably ws my tempermental ones in 3 weeks. Good luck!

Thanks for the information. I started the vinca indoors. When do those of you in zone 5 start seeing sprouts? This is my first year ws and I've seen nada yet.