Posted: 23/07/2013 at 12:36
Unless the seeds were already formed then they will not mature in removed flower heads. Since you get a lot of seeds from just one Dianthus flower, then why not just leave few on the plant to ripen proprerly ?
Storage is easy, once dry, put the seeds in an envelope and store in the Salad compartment of a fridge. Or, sow them straight away. They normally germinate within a couple of days and will survive the winter as long as they do not get too wet or frozen solid.
As said hybrids do not come true and a fair number do not set seed at all. Cuttings are the only way to get true plants.