This disclosure is for an automated canopy greenhouse having a motor driven canopy that is pulled over curved arch supports. The greenhouse has a generally rectangular base framework to which the arches are attached, the outside of the structure having the general shape of a cylinder cut lengthwise and resting on its flat side. A canopy or tarp is wound around a drum positioned near the bottom of one of the long sides. A shuttle bar is attached to two trolleys each of which ride on an arch at each end of the greenhouse. The trolleys are motor driven. One end of the canopy is attached to the shuttle bar and closes or opens the greenhouse as the trolleys and shuttle bar are moved. Inside the drum there is a torsion spring that is preloaded to balance the load of the canopy and associated hardware as the canopy is being raised or lowered. Successive greenhouse units may be attached to a first greenhouse unit that has the motor, and tarps on the successive units may be closed or opened using the same motor.