She knew that there could be a spell put in trees, and she was familiar from the time she was born with the way bottle trees kept evil spirits from coming into the house — by luring them inside the colored bottles, where they cannot get out again.
—Livvie, by Eudora Welty

The bottles are hung upside down on the tree branches with the neck of the bottles facing the trunk. The legend says that at night the evil spirits enter the bottles and become trapped. When the morning comes, the spirits are destroyed by the heat of the sun.
I have read that the practice of setting up bottle trees to ward off evil spirits was brought to America during the slave trade. Bottle trees have been very prevalent in the southern states for hundreds of years.
For my husband and I, the bottle tree brings us beautiful color to our garden. We enjoy the way it sparkles in the moonlight and shines in the sun.