I don't think it is multi stemmed/herbaceous, but you can take cuttings. but they will need to be kept frost free.
you can do stem or root cuttings. it is classed as a tender perennial in the uk.

https://www.rhs.org.uk/advice/profile?pid=638

Thank you very much. I'm really surprised about the classification, because I am in the north and the plant just loves the ground its in. Stayed safe right through our harsh winter. I'll try some cuttings and thank you once again for your speedy response.