Is each blade of grass an individual plant or not?
Each blade of grass is part of the grass plant and may have multiple blades.  Clumping grasses, when mature, can spread producing multiple shoots with additional blades.  The number of blades would depend on the type of grass and individual seed, but the clumping grasses tend to produce 10-16 leaves/blades.    



Source: Poaceae - Wikepedia