Lower the height of the. The primary means of renovating older trees is through judicious and properly selected pruning cuts. Apple and pear trees are most easily. Take heart—it is almost impossible to kill a mature, overgrown apple tree by pruning it, and most of the complicated pruning takes place in the. First, the care of aged, high-topped apple trees is laborious and expensive. Second, the fruit quality is generally poorer on older trees than on young, well grown.