Fruit maturity may be indicated by the appearance of reddish streaks at the stem end in purple varieties, or by a change from green to light green in green varieties. In some loose-seeded varieties, the fruit produces a hollow sound when tapped. The flowering period varies by variety from 4 to 14 weeks. Fruits grown on the same tree therefore vary in expected maturity dates. A minimum harvest size requirement is the best check and should be developed for each variety.
Fruits are still hard when mature, ripening only after being picked.
Mature fruits are full sized, have brown seed coats, and may change color slightly or lose glossiness. Mature fruits are usually picked at weekly intervals for a month or more, the largest fruits being selected each time. Some avocado varieties, particularly of the West Indian race, fall from the tree when physiologically mature. As a result, these varieties have to be harvested before they fall. In varieties from the Guatemalan race and its hybrids, the fruits remain attached to the tree for as long as three or four months after physiological maturity has been reached.