Protective covenants are usually recorded and are still applicable and valid unless and until a court orders otherwise or deeds are recorded eliminating the protective covenant. In terms of requiring the shrubbery removed, you have to determine if the protective covenant was something recorded in the registry of deeds and part of every parcel that is part of the Homeowners' Association or if this is strictly a bylaws by the HOA. So, in terms of the restrictive covenant, despite no fees and despite the lack of officers enforcing the restriction or prohibition, if indeed it is recorded, then yes it is enforceable by the HOA to force these individuals to remove the shrubbery.