Yes it can be put on grass. You may even want to consider not installing the floor boards. This way your plants would have even more root access. The planter is plenty deep as it is (11") but the floor is not really needed if you install your planter directly over the ground. The planter is made of cedar and is made to be left outside in any weather. We live in Upstate NY and all of our cedar planters are left outside with no problem. These are quality planters (thick deck boards).