An African-American practice of placing bottles and other luminous objects such as pie tins and ribbons onto the branches of dead trees. Slavery brought this custom to the Americas as slaves continued their West African tradition of attaching shiny objects to trees. The bottle tree tradition holds that evil spirits are attracted to the bottles and are trapped inside. When the winds blow, the low howl emitted from the bottles is said to be the sound of those spirits trapped inside.
The bottle tree tradition survived into the late 20th century in the rural South. Travelers and anthropologists noted the existence of bottle trees in the eastern Carolinas and southside Virginia in the late 1990s, so presumably the tradition has continued into the 21st century in America.
A photograph of a bottle tree during the 1930s:
http://www.olemiss.edu/mwp/dir/welty_eudora/bottle_trees.html
Excellent works on diasporic linkages between Africa and the Americas:
Mechal Sobal, The World They Made Together: Black and White Values in Eighteenth-Century Virginia, Princeton University Press (Princeton, NJ, 1987).
Robert Farris Thompson, Flash of the Spirit: African and Afro-American Art and Philosophy, Random House (New York, 1983).
Robert Farris Thompson and Joseph Cornet, The Four Moments of the Sun: Kongo Art in Two Worlds, National Gallery of Art (Washington DC, 1982).