hi had a go this summer bought 9 plug plants from a local garden centre and had alot of sucess. Grown quite tall, reds, greens and variagated not as lovely as your photo's bit i have taken lots of cuttings
I put them in a milk bottle full of water and they all rooted
planted them up and i got lots of new plants
going to keep them in a box in house for the winter my very first try with them really pleased your site really helpful learn something daily