Most fruiting trees (and shrubs) need cross-pollination, that is, pollen from another cultivar, in order to produce fruit. Even those reputed to be self-fruitful (that can produce fruit in contact with their own pollen) will bear more abundantly when there is cross-pollination (pollination with another variety).
The classic solution is, of course, to always plant at least two compatible varieties in proximity to one another. And proximity does not necessarily mean a few yards apart: it can be 100 feet (30 m) for many fruit trees! Of course, the two varieties have to be in bloom at the same time, so an early bloomer and a late bloomer of the same species would not be a good match. And only apple trees will pollinate apple trees, only pears will pollinate pears, etc. And I won’t even get into the complications of plum pollination, where European plums will only pollinate European plums, Japanese plums, only Japanese plums or Japanese hybrid plums, etc.
All on Its Lonesome
But what do you do if you have only one fruit tree and there are no others nearby? Or you have two, but, for whatever reason, one of the pair isn’t in bloom this spring? For that, you’ll have to do a bit of matchmaking!
When your tree starts to bloom, locate an appropriate match (a different cultivar of the same species) and ask the owner if he can share a branch. Bring the blooming branch back to your plant and set it out near your tree in a bucket of water. Bees will then go from the cut branch to those on your tree and bring pollen back and forth, pollinating the tree’s flowers. When flowers fade, chop up the cut branch and add it to the compost. And enjoy your harvest later in the season!