A greenhouse is a structure with a glass or plastic covering that is used for growing vegetables, flowers, fruits and herbs throughout the year and with minimal extra heating or cooling. Incoming solar radiation is trapped within the greenhouse, warming the inside of the structure. Greenhouses can range in size from a small shed to very large buildings.


Greenhouses can also be used to nurture vegetables and flowers in late winter and early spring when the outside temperatures are too low for crops. Plants can then be transplanted outside as the weather warms. Greenhouses have become increasingly important at high latitudes where winters are very cold. Large greenhouses covering more than 200 acres of plants and vegetables are now becoming common.


The number of backyard hobby greenhouses has also been rising rapidly in the past decade. Garden greenhouses can be freestanding or annexed to the side of the house. A greenhouse attached to a house is also known as a “lean to greenhouse”. A lean to greenhouse offers the advantage of easy access as well as the ability to share water and electricity from the main building. However, it is often a challenge for one to find a suitable attachment wall that gets the right amount of sunlight needed for the plants grown. On the other hand, a freestanding greenhouse would require its own framing and foundational flooring. Within the closed environment of the greenhouse, plumbing for irrigation and wiring for heating/cooling also requires detailed planning. Pests, diseases, heat and humidity must also be strictly monitored and controlled.


Greenhouse crop pollination can be accomplished by electric vibrators or mist blowers, or by striking overhead wires with a broom handle while walking down rows of plants such as tomatoes. This would ensure the transfer of pollen from anthers to stigmas of flower blooms, which is necessary for fruit set. Automatic vibrator systems which shake the overhead wires either longitudinally or across the wires can also be implemented. An advantage of an automatic pollinator other than labor saving is that it could be adjusted to operate every day for a few seconds at set times.


For natural pollination, bumblebees are the pollinators of choice for most greenhouse operators. Commercially available bumblebees start foraging earlier in the morning and visit flowers more frequently at cooler temperatures than most insects. Bumblebees give a much higher percentage of flowers that produce harvestable fruits.

To many home gardeners, the greenhouse has become a little place that provides personal satisfaction, relaxation and emotional fulfilment.