Abstract: A retractable cover for protecting agricultural crops against radiation frost. The polyethelene film cover lies atop a static rigging comprised of rows of posts permanently anchored in the earth and wires joining the posts. An elongated sheet rake extending the length of one row is attached to one side of the cover and is adapted to move the cover between a covering position and a retracted position adjacent a location where the cover is connected to the posts. Winch driven cables are used to move the sheet rake.