Blossom Rock was born on August 21, 1895, in Philadelphia, Pennsylvania. In her youth, she performed on the vaudeville stage with her older sister, actress/singer Jeanette MacDonald, and later went on to a career in movies, television, and Broadway. She is probably best remembered however, in the role of Grandmama on The Addams Family TV series (1964 -1966).
Although Grandmama was portrayed as the mother of Morticia in some later incarnations of The Addams Family, when the role was played by Blossom Rock in the original sixties series, she was the mother of Gomez. The part of Morticia's mother, Granny Frump, was played by Margaret Hamilton, who was the Wicked Witch of the West in The Wizard of Oz.
Grandmama Addams as she was depicted in cartoon form by her creator, Charles "Chas" Addams.
Blossom Rock died on January 14, 1978, at the age of 82.