Abstract: This invention is directed toward a rotating arm that can quickly and easily cover and uncover a greenhouse. The invention comprises a base unit to which is attached a rotating arm. The base unit is secured into cement and the rotating arm unit is attached at its end to a tarp. As a worker rotates the arm, the greenhouse tarp is quickly moved in the direction or rotation. A greenhouse with one of these inventions at either end can be covered and uncovered by a single person in a matter of seconds and removes the need for the motors and complicated apparatus associated with the prior art.