Apple harvest season is between August and October. Different varieties of apple mature at different times, so the best month to pick them varies. Depending on the variety, apples mature after 100 to 200 days of growth.
Apples should be picked when their background color is no longer green and when they have reached their full color, which varies by apple variety. When an apple is ripe, the stem parts readily from the branch when a person cups the fruit in her hand and gives it a slight twist around and then up. Mature apples have brown seeds, while immature apples have white seeds.