Question
My Mother's Norfolk Pine is too tall (5') for the stand it sits on and she does not want it on the floor. My Dad wants to plant it outside (in northest PA) next spring. Will it survive as a tree in this climate? I say cut off the two tall outside trunks and the small center one would continue to grow. What is best?

Answer
Norfolk Island Pine is an excellent house plant in your locality. This tree is from the Philippines and the sub tropical pacific.
Although  the tree perform well in hardiness zones of 7-8 it will perform better in the landscape in hardiness zone of 9-10. PA is more zones 5-7 so I would not think it will do well outside.

Norfolk pines do not respond well to pruning the growing leaders. These are not easily pruned because you can't just cut a >frond or tip and expect new growth. In the spring, only prune new buds just when they are beginning to emerge and are still light green in color. Remove just the tip which will include about three soft, needle-like leaves the same way you would go about bud pruning a Juniper. In a few weeks to a month, two new buds should take the place of the missing buds. If you pinch a bud wrong, new growth at the tip will cease. NIPs are one of those trees which you should practice bud pinching on several inexpensive practice plants first to develop an eye for pinching at just the right time.