In accordance with applicability requirements of underlying district regulations, the owner of the development, enlargement or converted building shall provide and maintain a planting strip. Street trees required pursuant to Section 26-41 shall be planted within such planting strip. In addition to such street trees, such strip shall be fully planted with grass or groundcover, except as provided in Section 26-421. Such planting strip shall be located adjacent to, and extend along, the entire length of the curb of the street.  However, in the event that both adjoining properties have planting strips adjacent to the front lot line, such planting strip may be located along the front lot line. The width of such planting strip shall be the greatest width feasible given the required minimum paved width of the sidewalk on street segments upon which the building fronts, except that no planting strip less than six inches in width shall be required.