A greenhouse, which is also known as a glasshouse or hothouse is a building where plants are cultivated.

Greenhouses range in size from the small garden sheds that many people use to grow their own fruit and vegetables, to very large buildings such as those seen at garden centres used to grow thousands of plants quickly in their correct environment.

Greenhouse Materials

Greenhouse Materials used are structures with a glass or plastic roof and frequently glass or plastic walls; it heats up because incoming solar radiation from the sun warms plants, soil, and other things inside the building. Air warmed by the heat from hot interior surfaces is retained in the building by the roof and wall.

The glass used for greenhouses works as a selective transmission medium for different spectral frequencies and it's effect is to trap energy (in the form of heat) within the greenhouse, which heats the both the plants and the ground inside it making for perfect growing conditions for many types of plants.

Greenhouse Humidity

Greenhouse humidity levels make for the perfect atmosphere as plants repirate and cause condensation and moisture in the air. Because of the enclosed structure, the humidity generated cannot escape into the atmosphere and so remains inside the building.

As an example, if you were to open a small window at the top of a greenhouse the temperature inside would drop very dramatically in a short space of time as the rising, warm air flows out into the atmosphere.

This principle is the basis of the autovent automatic cooling system. Greenhouses thus work by trapping electromagnetic radiation and preventing convection.

Growing Plants in Greenhouses

Growing Plants in Greenhouses is an economical and productive method. Greenhouse effects are most predominantly used for growing flowers, vegetables, fruits and tobacco plants in colder climates that otherwise would not sustain these types of plants.

Bumblebees are the pollinators of choice for most greenhouse pollination although artificial pollination is sometimes used as authenticity does not matter.

Besides tobacco, many other plants are grown in the greenhouses throughout the winter and spring and then moved, or transplanted, outside in the summer where the weather can sustain them without the need for artificial heat.

Started plants are usually available for gardeners in farmers markets at transplanting time.

Greenhouse Maintenance

The closed environment of a greenhouse has its own unique requirements, compared with outdoor production. Pests and diseases, and extremes of heat and humidity, have to be controlled, and irrigation is necessary to provide water.

Significant inputs of heat and light may be required, particularly with winter production of warm-weather vegetables. Special greenhouse varieties of certain crops, like tomatoes, are generally used for commercial production.