We moved a Ponytail Palm for a client and in doing so some of the leaves (the whole top) broke off. What care should be taken to ensure that it grows again? Note: it is a very large Ponytail Palm, and has two main stems each with several smaller stems. It is on 2 of these smaller stems that the "heads" broke off. Will it grow again where it broke off, or should one do something to prepare the stem to grow again?