a plurality of plow units are mounted to a main frame of a plow system for rotation about their vertical axes . the plow units are spaced at equal lateral increments and at uniformly increased distances from a pivot connection between the main frame and a traction vehicle . the plow units are ganged together by means of a guide beam ; and a power actuator controls the motion of the guide beam in rotating the plow units so that their cut lines take a predetermined position relative to the main frame . as the plow system is then used to plow ground , the main frame swings about its pivot connection to the tractor until the plow units line up with the direction of travel of the tractor , thereby adjusting the spacing between plow units automatically . the rear plow unit is mounted to a tail section which is pivotally mounted to the main frame and includes a rear wheel for supporting the distal end of the main frame and for steering the system as the tractor turns . a second power actuator is adapted to lift the main frame relative to the rear wheel for adjusting plow depth or pulling the system over ground without plowing it .