Good Evening! Three years ago I received two 12" small vases with lucky bamboo. They are magnificently huge with leaves almost 12" themselves and very full. I haven't pruned, and of course, they drape over my dresser with the weight. How do I prune, where do I prune, and how much do I prune? Please respond to firstname.lastname@example.org with the subject heading "bamboo". Thank you in advance for any advice!