Many commercially grown apples today are hybrid fruits that are the result of cross pollination. Orchard growers cross pollinate fruits as a method of creating hybrids that are stronger and more resistant to diseases and insect attack. In addition, some fruit trees, such as certain species of apple, are not self fruitful. These trees must be cross pollinated in order to produce fruit at all. Cross pollinating apple trees is easy to accomplish.
Research apple trees to discover which tree species are self fruitful and which are not. Good sources for information on apple trees include your county extension office, master gardener program or local apple tree nursery. Select apple species that are not self fruitful for cross pollinating.
Plant crab apple trees in every third row of your orchard as the pollinating agent. Apple trees must have the first and largest blossom to open in a cluster pollinated in order for the best fruit set. This blossom is known as the king blossom. Since crab apple trees have the longest blooming time, they are more likely to be open and distributing pollen when your other apples blossom.
Place bee hives in your orchard. Bees are the most reliable pollinator of apple trees. Some bee hive owners will rent out bee hives for temporary use during the pollinating season. A hive must be located closer than 100 feet to the apple orchard in order for the bees to effectively pollinate the trees. Wind action will also help to pollinate apple trees. You should use one hive per acre of apples. Place bees in the orchard one to two days before the king blossoms open.
Supplement bee activity by hand-pollinating apple trees. This is important in years when adverse weather delays the opening of apple blossoms. To hand pollinate apple blossoms, collect pollen from crab apples using a paint brush. Brush the pollen into the center of the apple blossoms of your fruit-bearing trees.