Though invented by Lovecraft in 1928 [needs confirmation], the name Cthulhu is probably derived from the Classic Greek word chthonic meaning subterranean, as apparently suggested by Lovecraft himself at the end of his 1923 tale The Rats in the Walls.
They're listed as a zone 5-9 plant but as a member of the hibiscus family, Rose of Sharon naturally prefers a warm climate. As a living fence, which is what you really want, you'll be much better off with some kind of evergreen. Juniper, spruce, pine, fir, there are many sizes and varieties to choose from.
Growth Rate. Rose of Sharon has a medium growth rate, meaning that it grows approximately 13 to 24 inches a year. A mature Rose of Sharon bush can grow between 8 to 12 feet tall with a 4 to 10 foot spread. The shrubs have a compact, upright growth pattern when young, but tend to spread out as they age.