Grass is the most common Item in the game appearing ~60% of the time. It can be formed into various complex Objects. Placing a GrassItem is worth 5 Points thus using an Imperial Bot on a Grass will cost you 5 points. If you place 3 Grass adjacent to each other, they form a Bush . If you place 4 or more Grass next to each other, they form a Super Bush, which gives more points. Grass, as with other objects, can be used to trap Bears.
Most objects are formed by placing 3 of the next object down together, so the amount of Grass needed follows the powers of three up until the Triple Castle, which requires placing 4 Floating Castles together.
This chart shows how much Grass is needed to form other objects, assuming that you do not use any Crystals or other objects.