A good answer could include planting the trees on the north-facing flank of a hill (passive) and providing overhead irrigation to allow the grower to give plants an ice coating (active). Apples grown in New York face their strongest threat during bloom-time. North-facing plantings partway up a hillside delays bloom-time to later in spring, reducing the odds of the plants experiencing a hard frost. Irrigation allows the grower to take advantage of the severe overall cold that can be associated with a freeze in upstate New York by using the cold to create a protective ice layer that can preserve the blossoms.
