The frame and greenhouse cover creates a protected microclimate for plants in your 40" long, flat-back Trough or Wallhugger VegTrug™. You can start planting earlier in spring and extend the growing season later into fall for an even bigger and better harvest. The steel frame installs in minutes with convenient push-fit connectors, and the reinforced polyethylene greenhouse cover has heavy-duty stitching and zippers. The cover slips snugly over the frame and attaches with strong VELCRO® brand tabs. Zips open for ventilation and easy access to crops.