I have a few cordylines in my garden, I take off two or three rows of leaves every Spring depending on the size of plant, more if it's quite tall,thus creating a trunk, but I don't peel them away from the tree, I cut them off close to it, and so the actual fleshy part of the trunk is still covered. I'm not sure if this is the right way really, but it helps to keep the snails and slugs out of the plants, and I think they look much more attractive. I have some cordylines which are from 4 to 7 years old and 5 to 6 feet tall, they are very healthy and flower most Summers..........hope this helps........welsh