Career

Originally from Portsmouth, Virginia, Carthan moved to the tree-lined block of Vernon Avenue between Tompkins Avenue and Throop Avenue in Bedford-Stuyvesant in 1953, but by 1964, only three trees remained. She sent postcards to everyone on her block and formed the T & T Vernon Avenue Block Association, which raised funds to buy and plant trees by throwing block parties. The City of New York supported her efforts: Mayor John Lindsay attended one of the block parties, and the City Parks Department provided trees under its treematching program

Eventually, Carthan would head the Bedford-Stuyvesant Beautification Committee.

She oversaw over 100 block associations which planted over 1,500 trees including those of the ginkgo, sycamore, and honeylocust varieties

Carthan spearheaded a campaign to save a 40-foot Magnolia grandiflora tree that was thriving far north of its natural habitat, by getting it designated an official city living landmark. She went on to found the Magnolia Tree Earth Center, an educational center.