Modern greenhouses are a solution for the farmer or gardener that seeks to see his or her fruits to mature and get nurtured even when the weather is not conducive. It was in England where grapevines grew in sunny gardens that the greenhouse was born. After trying out the use of inclining walls to catch more of the sun's rays, it was found that a building would be better suited as leaves need to shun the often frost filled breezes that commonly blew in cold English weather.

Here's what Wikipedia has to say about the topic:

"A greenhouse is a structure 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. These structures range in size from small sheds to very large buildings."

Glass And Plastic Are Ideally Suited To Grow Plants Etc.

Since greenhouses were meant to allow farmers and gardeners to grow plants and flowers and fruits even when the season was not right, they thought of buildings that were also equipped to meet various functions. Glass covering provides an ideal environment within which to grow plants, vegetables, flowers as well as fruits since it allows for plenty of sunlight even during winter. The function of a greenhouse is to provide solar as well as thermal radiation through the use of transparent glass, which should be thick enough to contain the thermal infrared wavelengths emitted by plants and soil, which help in growing the plants etc.

The plants or vegetation or fruits growing inside the greenhouse absorb solar radiation, which enables them to stay warm, and when the thermal infrared radiation emitted by plants within the greenhouse is kept within, the heat within begins to build-up. There is however, not much difference between a glass and plastic greenhouse as both are equally effective.

In essence, the greenhouses are structures having glass or plastic roofs and also walls that heat up due to solar radiation that keeps plants, soil as well other things heated up. With the insulation available, the heat within rises which is good for everything within.

Greenhouses are available in a number of sizes and the glass with which they are built act as a medium for transmitting different spectral frequencies effectively trapping energy inside the confines that keeps plants and soil heated up. The air close to the ground is also quite hot and when it cannot escape causes the trapping of electromagnetic radiation while also hindering convection.

Common uses of such buildings include growing plants, vegetables, fruits, flowers as well as tobacco. For the purpose of pollination, bumblebees are most often used though other types are also used in addition to artificial pollination. Tobacco is often grown in the winter in greenhouses and transplanted outdoors when the weather turns warm in the summertime.

Greenhouses also have their own peculiar requirements with regard to pests and diseases as well as extreme humidity and heat, which must be kept at acceptable levels while there should also be provision for irrigation.

If you are still hungry for more information, here are a few ideas:

1) Ask a friend - you'll be surprised at how much your friends actually know

2) Libraries - try the public library or the local university library

3) Dictionary - don't forget about something as simple as the dictionary