Are you interested in gardening year-round? Then shop for greenhouse kits which contain everything you need to build a greenhouse. While shopping you will discover that greenhouses have a fascinating history. While greenhouses might seem like a modern invention, growing plants in controlled environments dates back to ancient Rome. History books tell us that Tiberius, a Roman emperor, ate a vegetable every day that was similar to the modern cucumber.
In order for Tiberius to have this vegetable every day at his whim, Roman gardeners used artificial methods similar to today's greenhouses. According to a description by Pliny the cucumbers were planted in carts, placed in the sun every day, and then brought inside for warmth. The food was stored in houses that were glazed with mica sheets.
The greenhouse was not modernized until pre-Renaissance Italy. Explorers brought exotic plants from the tropics and kept them indoors at night or for winterization. These early greenhouses were not adequate for providing balanced heat, but today's greenhouses and greenhouse kits have none of these difficulties.
Early greenhouses have traditionally been seen as signs of wealth. However, as exploration into the fields of science and botany grew, greenhouses quickly flourished at universities. The French used greenhouses to keep oranges from freezing and as pineapples became popular they were tended to indoors. During the 17th century in Europe, greenhouses continued to grow in size as better glass construction techniques were found. In France, the Palace of Versailles had a greenhouse that was more than 500 feet long and over 40 feet high.
We associate the 19th century with large elaborate greenhouses of the Victorian era. Larger greenhouses were built in England, London, New York, and Munich.
Today's greenhouses come in two varieties: glass and plastic. Commercial glass greenhouses utilize technology for mass production of vegetables and flowers. These greenhouses are filled with high-tech devices that heat, cool, and control lighting. The functionality may be so high-tech that is controlled by a computer.
Greenhouse kits are much simpler than these high tech devices. And you don't have to know how the kits work, but most gardeners find it helpful to have a basic understanding of how greenhouses function.
Greenhouses use different transparencies of glass to work with thermal infrared radiation and solar radiation. While the glass allows most of the solar wavelengths to pass through it blocks the thermal wavelengths that the plants and soil inside the greenhouse give off. In other words, solar radiation is allowed to pass through from outside and heats the plants, vegetables, fruits etc. inside the greenhouse. The longer thermal wavelengths are trapped by the glass so they can I get out and the key keeps building up.
This is the most conventional explanation of how greenhouses work. Scientists complicate this notion by observing that polyethylene greenhouses function just as well as glass greenhouses even though they allow infrared radiation to escape. The easiest way to address this apparent contradiction is to note that the ground absorbs radiation from the sun and this increase in temperature is conducted to the air in the greenhouse which then warms and expands. The cooler and denser air sits at the surface and picks up more heat from the warmth ground. Therefore, the ground's absorbed radiation heats a layer of air that is helpful to your plants.
Anne Clarke writes numerous articles for Web sites on solar energy, parenting, fashion, and home decor. Her background also includes teaching, gardening, and health and fitness. For more of her useful articles on greenhouses, please visit Orchid Greenhouse.