Man has always tried to find ways to alter nature to his advantage. He collected seed and prepared land to sow it in, and he caught and tamed animals to raise for meat and milk. To try to increase the length of the growing season so food was available for longer, and to grow plants from warmer climates, man developed the greenhouse.
The Romans were the first recorded pioneers of the greenhouse. The emperor Tiberius ate a cucumber-like vegetable daily, and artificial methods of growing were used to make this available. The plants were wheeled into the sun by day, and stored at night in warm conditions. They used fires outside a building to increase the internal temperatures, and later semi-transparent mica was used to cover the roof of buildings containing the plants.
Not until the 13th century, after glass had been invented, were the roman records of their work discovered, and the first greenhouses began to appeared in Italy. The first modern greenhouses (called botanical gardens) were built to house the exotic plants that explorers brought back from the tropics. With the growth of the science of botany, greenhouses spread from the estates of the rich to the universities. The French called their first greenhouses ‘orangeries’, since they were first used to grow oranges in cool climates. They were later used for pineapples and other exotic plants.
Early greenhouse designs were of wood and stone or brick, built on south facing walls, and heated. Due to a glass tax (window tax) very little glass was used at this time, but once this tax was removed in the 19th century, a whole range of glass houses appeared. Steel work replaced wood, and designs became more complicated. Examples of this are the buildings at Kew Gardens, the Palm House, and the Crystal Palace built in 1851
Mass produced greenhouses appeared around 1950, made from wood, aluminium and steel. Later new ideas were developed, like the hoop or tunnel greenhouse, and the Geodesic dome. All manner of innovations have been made – automatic windows and watering systems, automatic shading, humidity and temperature control, heating systems, and the use of hydroponics.
In cool climates, the greenhouse has become a very important factor, as they allow certain crops to grow throughout the year. They also offer protection not only from cold weather, but dust storms, high winds, blizzards and many airborne pests and diseases. The enclosed area also means easier climate control, and greater control of spraying for treatments for disease and of fertilizers.
Tags: botanical garden