Why doesn't Spanish moss grow on the oak trees along Carrollton, Napoleon and St. Charles avenues and most of Magazine Street between Audubon Park and the zoo?
If there's no moss on the trees, it's because moss hasn't "colonized" there. New Orleans has many suitable trees on which the moss could grow but doesn't. I have a 100-year-old oak in my backyard that has never been a home for moss. If folks want moss to grow on a tree, they could hang the moss there, and if it likes the location it will flourish.
Spanish moss — also called Florida moss, long moss, or graybeard — is not a true moss. It is an epiphytic plant, which grows on another plant but does not rely on the host for nutrients. Epiphytes make their own food. Sometimes they are called air plants because most have aerial roots. Spanish moss, however, does not have roots. It uses its long, thin, scaly stems to wrap around the host tree and hang down from its branches.
Spanish moss will grow only on trees, not fences, telephone poles, buildings or even vines. Whatever clumps of Spanish moss are found on these surfaces have fallen there or have been blown from tree limbs by the wind.