I have a couple clematis I'd like to propagate and would like to know how best to take cuttings. What is the best time of year for it, do they do best with bottom heat, does rooting hormone help, if so which kind? What is the best material to root them in? Is the method any different for different types? One I'd like to do is an alpina, the other is durandii. Any suggestions and advice would be greatly appreciated!