The elements can be harsh and cruel to young plants. Tropical plants require a specific microclimate to grow in temperate regions. These are just two of the many reasons gardeners utilize greenhouses. Greenhouses provide a controlled, sheltered building for plants to grow unhindered. Greenhouse film is a type of plastic covering used to shelter the plants inside of a greenhouse from the larger world outside.
Traditional greenhouses use glass coverings to allow light in but keep chilling winds out, as well as to preserve moisture and humidity. Modern greenhouses can be constructed with greenhouse plastic to achieve this same effect. Greenhouse film is lighter, easily replaceable and more cost-effective than traditional glass coverings.
Greenhouse film, also called greenhouse vinyl, is a thick, industrial-grade sheet of synthetic material. Available in opaque or transparent forms, agricultural plastic can be clear or tinted with a number of colors. It is sold in long rolls and is usually available at garden supply centers, nurseries, home improvement stores or building supply houses.
The malleable form of greenhouse film allows gardeners to shape the covering to their individual greenhouse. A greenhouse frame, typically made from wood or metal, is little more than a skeletal frame. The plastic is layered over the frame to create the greenhouse walls and ceiling.
Greenhouse plants benefit from the covering. Tropical plants that require high amounts of moisture enjoy the humidity trapped by greenhouse film. Delicate semi-shade plants benefit from the diffuse sunlight, where direct sunlight might harm the foliage or leaves. Hardy plants gain protection from scavengers such as deer and squirrels.
Gardeners who cover their structures in plastic face regular repairs. Since greenhouse film isn't as sturdy as glass, it is prone to rips and tears, which must be remedied with a special adhesive tape. Greenhouse plastic shrinks in cold temperatures and expands in warmer ones. The light of the sun heats up metal supports, causing burns or melting on some greenhouse plastics. With all the wear and tear, greenhouse film needs to be replaced every four to six years, as indicated by wear and the manufacturer.
The use of greenhouse film isn't just limited to greenhouses. A miniature greenhouse seed tray, constructed from old wooden picture frames or window frames, makes use of the sturdy plastic to concentrate light on delicate seedlings. In the event of an impending frost, greenhouse plastic can be layered over plants to provide a physical barrier against scorching.