An Introduction to Greenhouses

Structure

• Greenhouses can be made in a number of ways. Traditional greenhouses consist of wood or metal frames with glass or plastic paneling, and, occasionally, a concrete foundation for added stability. Inexpensive greenhouses can be made with hoops of PVC piping and plastic sheets. The structure of a greenhouse depends on its purpose and the budget of the builder. Greenhouses used in small gardens may be made of plastic while commercial greenhouses may invest a great deal of money for fans and other supplies.

Function

• Greenhouses work because they trap heat and moisture inside their walls. This creates a warm and humid environment where plants can be grown easily. Plants can have longer growing seasons or be grown out of season with proper care and lighting. This makes greenhouses valuable to gardeners and food producers. Greenhouses are often used for growing exotic plants, although using them for food and garden plants is a common practice.

Size

• Greenhouses can range from small enough to cover only a single row of plants to large enough to house entire crops of food. The size of a greenhouse affects its cost, as glass and plastic panels, ventilation systems and supplies can become very expensive. Greenhouses also contain either tables or systems for growing plants, which need to be maintained.

Types

• A traditional greenhouse is one that contains tables and rows or containers of plants. This is the type of greenhouse found in most garden centers. However, there are other types of greenhouses. Permaculture greenhouses use all available vertical and horizontal space to grow plants. Hydroponic greenhouses combine the principles of a greenhouse with a moving-water system to grow plants or raise fish.

Considerations

• A greenhouse should have unrestricted light for the entire day. If it's attached to another building, it should face south for full light. In certain climates, greenhouses can overheat or become too humid, which can damage the plants. Investing in a climate-control system reduces this problem.