While some cultivars of avocado are self-pollinating, others are not. When these flower, each blossom opens for only two days. On the first day, the female pistil is receptive. On the second day, the pistil is no longer receptive. The same flower, however, sheds pollen from the stamens, the male portion. This means that the flower cannot pollinate itself. It needs a pollinator which physically transfers pollen from one flower to another. The most reliable pollinator is the honey bee. Whether self pollinating or not, all avocado trees can benefit from the help provided by honey bees.
Talk with local bee keepers to see if they can locate a hive near your avocado trees. You may be able to work out a deal to trade pollination services for avocados later in the season.
Consider becoming a beekeeper yourself. If you have only a few or even one avocado tree, it will probably be easier to start keeping bees yourself. This is an interesting hobby that takes little time and investment.
Mow the area around the avocado trees to reduce the amount of blooming plants that will be competing with the avocados for the bee's interest.
Observe the avocado trees for flowering and place the bee hives before or at the onset of blooming. Position the hives in the center or along the longest outer edge of the grove. There should be two to three hives per acre of avocados. Anything less than a quarter acre will be well served by just one hive.
Ensure that the bees have a clean water source for drinking. Do not feed bees during the bloom period as this may distract them from visiting the avocado flowers.
Observe the number of bees working each tree. Mentally divide one tree into four sections. Count the number of bees working each section for 15 seconds. Repeat this for the three other sections. If less than 20 bees are noted, another hive may be necessary for proper pollination.
Leave the hives undisturbed until the blooming period has ended. Do not apply any sprays to the trees during the time frame bees are present.