First of all, no heart failure. You can do either or both of the following with all of the cuttings. Stick them in water and put them in a window that gets light and watch all the roots grow, them pot them up in some miracle grow potting soil. Or you can put the end of each cutting in some rooting powder and pot them in some miracle grow. Voila, plenty of new plants to have or give to friends. As for cutting back, I just cut mine back as much as I need to or looks good to my eye. Last year my daughter hacked one back to, what looked like almost nothing and in a matter of 3 weeks it was full, bushy and enormous all over again. She wanted to do it again but said no dice kid, once is more that enough. Just prune to look good to your eye, you will be fine.

I agree they are almost indestructible and still look good when very tall, but if I cut them back now, they are going to look pretty terrible for a while. Also something has begun to eat the buds: any ideas?? I will cut them back when I take them inside. Can I grow them outside until then They did great indoors last year.