A row unit of a seeder includes a frame configured to be coupled to a toolbar of the seeder. The row unit also includes a single opener disc rotatably coupled to the frame and a closing system. The closing system includes a closing disc arm pivotally coupled to the frame, and a closing disc rotatably coupled to the closing disc arm. The closing system also includes a closing disc actuator coupled to the closing disc arm. Furthermore, the closing system includes a packer wheel arm pivotally coupled to the frame. The packer wheel arm and the closing disc arm are configured to rotate independently of one another relative to the frame. The closing system also includes a packer wheel rotatably coupled to the packer wheel arm. Furthermore, the closing system includes a packer wheel actuator coupled to the frame and to the packer wheel arm.