According to folklore experts, ..... .

Rooted in an African tradition of capturing evil
spirits in glass bottles, "bottle trees" were once
common in the rural pails of the southern
USA. Tradition held that the night wind
blowing past the glass caused trapped spirits to
cry until the morning sun destroyed them.
Folklore experts believe the practice came to
the US with slaves from central and western
Africa. Today, whites as well as blacks erect
bottle trees in their gardens by placing various
coloured bottles on the branches of trees.
Though the trees look much like the ones of
the past, those constructed nowadays are
simply for decoration as the belief in the evil
spirits of the night has died away, leaving
behind only the physical form of the traditional
protection against them.