Many fruit trees require a pollinator, but what does that mean exactly?   Although there are fruit trees out there that are self fruitful (like some cherry tree varieties for example), others will require a recommended pollinator in order to produce fruit (like apple trees). Basically, fruit is produced when the female parts of a flower are exposed to pollen, which is what we mean when we say "pollination."  Pollen is produced by the male parts of the flower.  Some flowers, called "perfect flowers", contain both female parts and pollen-producing male parts.  Plants with perfect flowers can sometimes pollinate themselves, but some have biological blocks in place that prevent self-pollination.  Other plants have flowers that are either male or female.  These require pollen-producing male flowers to be accessible to the female flowers.  Sometimes, male and female flowers grow on the same tree.  In some species, though, male flowers grow on male trees and female flowers grow on female trees.

stamen pollen Karwath close up
Pollen-producing stamen, © 2005 Karwath

In order for pollination to take place, the flowers have to be compatible, which usually means that they have to be the same species, since every species' pollen is unique. If you want to pollinate an apple tree, you'll need apple pollen. Furthermore, you will want your pollen-producing flowers to bloom at the same time as your fruit-producing flowers.  If the flowers bloom at different times, the pollen from one might not be around when the other is ready to receive it. If you are interested in growing fruit, you will want to find out if your tree's species can self-pollinate.  If not, you will want to find another tree that is compatible.

 bee pollen close up
© 2007 Guerin Nicolas

In some cases, just having a source of pollen is not enough. Sometimes you need a pollinator, or an agent that moves the pollen from one flower to another.  For some plants, this can be as simple as wind.  Other plants need birds, insects, or other animals to move their pollen.  It depends on the natural shape of the flowers.  In almost all cases, you can move the pollen yourself, but this can be tedious.  It's best to make your tree available to its natural pollinators and let the wind and wildlife do it for you. For more resources on pollination and compatibility, check with an arborist or your local county extension agency.  If you have a local university with a horticulture department, that is another good resource.  When researching online, keep in mind that .edu websites are the most reliable sources for up-to-date, accurate information.