Experts and BHG readers answer.
If there are no other varieties of avocado tree nearby, your avocados may not have gotten pollinated. If the flower doesn't get pollinated, it will fall off. Avocados fall into 2 pollination groups. You should have at least one variety from each group to get the best results. Of the varieties commonly grown in California, group A is comprised of: Anaheim, Hass, Mexicola, Pinkerton, and Reed. Group B is made up of: Bacon, Fuerte, Nabal, Stewart, and Zutano.