Hot summer sun can burn tender seedlings and make cool-season crops like lettuce turn bitter. The UV-stabilized polyethylene VegTrug Shade Cover cuts summer sun by 50%. It covers the top of the VegTrug and extends 10" down the sides. This leaves the lower sides open so air can circulate freely around plants. To install, simply remove the greenhouse cover from the frame, and then install the shade cover in its place, securing it with the VELCRO® brand tabs.