The plastic sheeting used on greenhouses is a polyethylene film. This material is inexpensive and is easy to use. The film can be cut to fit and can be secured a number of ways.
The plastic sheeting used on greenhouses is not very durable but can be easily replaced. It lets in a good amount of light, but does not retain heat as well as acrylic panels. This film is best used on small or portable greenhouses.
Plastic sheeting can also be used to insulate an existing greenhouse with minimal interruption of light. Gardeners can be commonly seen installing a layer or two of polyethylene film inside the greenhouse in the fall to brace the plants for the cold months ahead.
