Apple Tree Pollination
In order to produce fruit, the flower of an apple tree must receive pollen from a different apple tree variety. This normally means that the homeowner or gardener should plant two different varieties in the same general area.
The actual movement of pollen usually occurs as a result of bees and other insects moving from flower to flower.
Apple trees flower at different times during the spring. They are usually classified as either early, mid or late season blooming. Generally speaking and early blooming variety and a mid-season variety will overlap allowing pollination to occur. Likewise a late season variety and a mid-season variety will also overlap enabling pollination. But an early and a late season do not normally flower at the same time so therefore can not be used as pollinators for each other. Bottom line, if the trees do not bloom at the same time, pollination can not occur.
To further complicate matters, some trees have sterile or incompatible pollen and can not be used to pollinate other trees. These varieties are called Triploids. If you choose to grow one of these varieties, plant an additional apple tree in the area to serve as a pollinator.