Hi Natalie.
Over here on the east coast of G.B. The winters can be so different from year to year. Last year we had several hard frosts, this year none. So to be safe. I take softwood cuttings in the Autumn (I believe you call it fall). then over winter them in the greenhouse. Phygelius are really easy, but I don't use rooting powder, as this seems to hinder them more than helping.