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.
The Rose-of-Sharon is valued for its large summer flowers produced at a time when few other plants bloom. It's tolerance of aerosol salt and occasional wet or drought periods make this a fine shrub for many landscapes. It is suited to formal or informal plantings, groupings, shrub borders, hedges and screens.