I do them from tip cuttings in spring before the plants bloom. You can take some now, though, from non-blooming stems. Look around the base of the plant for this growth.

I use .1% IBA/talc rooting hormone (Rootone is one brand), a medium of soilless potting mix/perlite 1:1 by volume. I have a mist bench in a greenhouse where they live until they root, but you can tent the cuttings in plastic in a shady spot and keep an eye on them, not letting them dry out. They're slow to root for a perennial -- six to eight weeks is typical.

Soeur

Thanks,I'll try that.

PP