Where C-1 Districts abut any residential district or an alleyway separating the two districts, a landscaped strip of not less than 10 feet in width shall be planted and maintained with appropriate vegetative landscaping materials. Such vegetative planting, including any architectural screens of fences, shall be planted or constructed and maintained at not less than five feet in height, except on corner lots where a clear sight area shall be maintained in accordance with Article XIII of this chapter.