All landscaped areas shall be finished with a natural topping material which may include,
but not limited to, the following: turf, groundcover, planting, decomposed granite
(two (2) inches minimum depth), river run rock, expanded shale, or bark. A pre-emergent
herbicide shall be applied to the ground prior to the placement of natural surface
materials (decomposed granite, river run rock, etc.) in any landscaped area to prevent
weed growth.