One of the great frustrations of growing a fruit tree in the home garden is not having the tree bear fruit. Major reasons for this occurrence are the lack of proper cross-pollination. While fruit trees may produce an abundant crop of flowers unless they are cross-pollinated by another variety of the same species fruit set and production will not occur. Pollination is the transfer of pollen from the anther of the male part of the flower to the stigma of the female part of the flower. If this pollination occurs in the same tree or other trees of the same variety it is considered self pollination. If pollination occurs from a different variety on the same tree or a different variety on another tree it is considered cross pollination.
Details on pollination should be provided on the tag of each tree when purchased, or sales and service personnel should provide this information. Unless you are an expert on pollination, or have an up to date fruit science book, mail order catalogs are good sources of information on pollination requirements.
Peaches,. nectarines, tart cherries, and most apricots are self pollinating meaning only one tree of any variety is needed to pollinate and set fruit to maturity. Most apples, pears, cherries, and plums need to be cross-pollinated by another variety. Thus at least two varieties are needed to produce a full crop of fruit to maturity. Some of the newer sweet cherries and pears are self-pollinating, but will produce larger and better crops if cross pollinated. Varieties must be of the same species or closely related to provide cross-pollination. For example plums will not pollinate apricots and apples will not pollinate pears. Sweet cherries will not pollinate tart cherries
It would be simple to recommend planting any two varieties of the same species to provide good cross-pollination and fruit set to maturity. However, varieties of the same species must bloom at a similar time, shed pollen that is both strong and viable, and cross-pollinate with compatible pollen. Information on the best cross pollinating varieties must be known before purchasing unless you purchase one of those special trees with three, four or five varieties grafted on them.
If the right trees are close enough together wind will transfer pollen but in most situations bees and other insects are needed to transfer the pollen. Sometimes you are lucky because one of your neighbors has the right variety to pollinate your tree. Sometimes you can also be unlucky because you have the right varieties for cross pollination but the weather or some type of pest keeps you from setting a full crop of fruit to maturity.
