Bananas aren't actually trees but herbaceous perennial plants that grow into a treelike shape. The plants are very cold-sensitive and only grow in semitropical to tropical regions. Native to Southeast Asia, bananas rank as the fourth most widely grown tropical plant in the world, according to California Rare Fruit Growers. Its purple buds lead to white flowers. Like all fruit, bananas can ripen on or off the tree as long as they are mature enough.
Examine the bananas daily as they reach maturity. The bananas should be close to their normal size, and the ridges on the back of the fruit should smooth out when they are ready to be harvested. The bananas will look filled out.
Look at the color of the fruit. You can pick them when they are light green with no ridge on their spine or when they are starting to yellow. If you wait until they are completely ripe, rodents might beat you to the crop.
Use a knife to cut the light green, almost ripe bananas from the tree. Hang the fruit in a cool and shaded place to allow them to ripen completely. You achieve a better flavor this way than letting them tree ripen all the way. The bananas will turn yellow, brown or red, depending on the variety, when they are totally ripe.