Measure a 4-by-8-foot rectangle in the area where the PVC cloche will be located.
Drive a length of rebar into the soil at each corner of the rectangle, with a hammer, and leave 4 to 6 inches protruding above ground.
Install lengths of rebar at 32-inch intervals, along the 8-foot side of the rectangle.
Cut four 7-foot lengths of ½-inch PVC pipe with a hacksaw.
Slide one end of a 7-foot pipe section over the protruding rebar, bend it gently, and slide the opposite end over the rebar on the opposite side of the garden bed. Repeat until four hoops are formed over the garden bed.
Construct PVC clips by sawing a small piece of ¾-inch PVC pipe into several 1-inch pieces. Remove one-third of the circumference of the PVC pipe with a hacksaw, leaving a C-shaped length of PVC pipe. These will form the clips that hold the plastic fabric to the hoop frame.
Cut a length of plastic sheeting into a 7-by-15-feet rectangle. Drape the plastic sheeting over the hoops, securing it to each length of PVC with three clips.
Secure any extra material at the ends with landscape pins, bricks, or heavy stones.