Raised landscaped islands, eight feet wide, at each end of a parking stall row of 15 or more continuous parking spaces. Such island shall be the full length of the parking spaces provided to prevent the encroachment of moving vehicles into parking spaces. In addition, if a parking stall row accommodates 40 or more spaces, an additional island, eight feet wide, is required. Thereafter, an additional landscaped island is required for every additional 20 spaces in the parking stall row. All required landscaped islands that are in addition to those at each end of a parking stall row must be spaced at regular intervals. The required landscaping to be included within these islands includes an appropriate mixture of shade tree, low-level planting and ground cover. A minimum of one shade tree or three low-level plantings shall be required for each island, with the remainder of the island consisting of ground cover.