Check the Calendar
On a calendar, mark down the day when your backyard Gala apple tree first produces blossoms. Depending on your climate and growing conditions, Gala apples will be ripe anywhere from 140 to 160 days after the tree blooms. Because the date range can fluctuate so widely, it's unreliable on its own but can be one of several clues that your apples are approaching harvest time.
Observe the Ground Color
Review the color of the Gala apple's skin in the indentation around the stem. In orchard terms, this is known as the "ground color." Specifically, look at the ground color on the part of the indentation that faces the interior of the apple tree. When the skin turns from immature green to a creamy yellow, the Gala apple is likely ready for harvest.
Take a Test Apple
If you suspect the Gala fruit is ready for harvest, pick a test apple and cut it open with a clean knife. A mature, ripe apple usually has dark brown seeds. Like the other indicators of ripeness, however, this is unreliable on its own but very helpful if you combine it with other ripeness factors. If the apple has passed all of your tests so far, take a sample bite of the fruit. This is a fail-proof test of apple ripeness. If the texture is crisp and juicy and the apple tastes sweet, your Gala apple tree is ready for harvest.
Harvest Your Apples
Unlike some other fruit trees, Gala apple trees must always be picked by hand. Grab a ripe apple in the palm of your hand and twist the fruit while simultaneously pulling up and away from the tree branch. The fruit should break off with the fruit stem still attached to the apple. Enjoy the apple right away, or store it in a refrigerator set to 32 degrees Fahrenheit. At this temperature, they may last up to six months before going bad.