Welcome to ATP, Rita. I agree about the hummingbird vine but find Class 2 and 3 clematises as easy as a vine can get. Not so with the entire "montana" clan, which can become enormous. I have more than 100 clematises and would have yanked them if they were a problem.
I battled the evil, but beautiful, Houttuynia cordata 'Chameleon', for many years and finally won the war but it was a horrible problem.
