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| title | chunk | source | category | tags | date_saved | instance |
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| Greenhouse | 4/4 | https://en.wikipedia.org/wiki/Greenhouse | reference | science, encyclopedia | 2026-05-05T09:02:41.007301+00:00 | kb-cron |
=== High-latitude solar greenhouses === Specialized designs exist to allow for growing of crops in the colder climates at higher latitudes. In northern areas of China such as Shenyang, slanted solar greenhouses are used to provide efficient, passive heating of crops. This heating has been shown to prevent crops from reaching lethally low temperatures, even when active heating elements are disabled. This style of greenhouse was first constructed in 1978, growing in popularity during the 1980s.
== Uses == Greenhouses allow for greater control over the growing environment of plants. Depending upon the technical specification of a greenhouse, key factors that may be controlled include temperature, levels of light and shade, irrigation, fertilizer application, and atmospheric humidity. Greenhouses may be used to overcome shortcomings in the growing qualities of a piece of land, such as a short growing season or poor light levels, and they can thereby improve food production in marginal environments. Shade houses are used specifically to provide shade in hot, dry climates. As they may enable certain crops to be grown throughout the year, greenhouses are increasingly important in the food supply of high-latitude countries. One of the largest complexes in the world is in Almería, Andalucía, Spain, where greenhouses cover almost 200 km2 (49,000 acres). Greenhouses are often used for growing flowers, vegetables, fruits, and transplants. Special greenhouse varieties of certain crops, such as tomatoes, are generally used for commercial production.
Many vegetables and flowers can be grown in greenhouses in late winter and early spring, and then transplanted outside as the weather warms. Seed tray racks can also be used to stack seed trays inside the greenhouse for later transplanting outside. Hydroponics (especially hydroponic A-frames) can be used to make the most use of the interior space when growing crops to mature size inside the greenhouse. Bumblebees can be used as pollinators for pollination, but other types of bees have also been used, as well as artificial pollination. The relatively closed environment of a greenhouse has its unique management requirements, compared with outdoor production. Pests and diseases, and extremes of temperature and humidity, have to be controlled, and irrigation is necessary to provide water. Most greenhouses use sprinklers or drip lines. Significant inputs of heat and light may be required, particularly with winter production of warm-weather vegetables. Greenhouses also have applications outside of the agriculture industry. GlassPoint Solar, located in Fremont, California, encloses solar fields in greenhouses to produce steam for solar-enhanced oil recovery. For example, in November 2017 GlassPoint announced that it is developing a solar enhanced oil recovery facility near Bakersfield, CA that uses greenhouses to enclose its parabolic troughs.
An "alpine house" is a specialized greenhouse used for growing alpine plants. The purpose of an alpine house is to mimic the conditions in which alpine plants grow; particularly to protect from wet conditions in winter. Alpine houses are often unheated since the plants grown there are hardy, or require at most protection from hard frost in the winter. They are designed to have excellent ventilation.
== Adoption == Worldwide, there are an estimated nine million acres (about thirty-six and a half thousand square kilometers) of greenhouses.
=== Netherlands ===
The Netherlands has some of the largest greenhouses in the world. Such is the scale of food production in the country that in 2017, greenhouses occupied nearly 5,000 hectares. Greenhouses began to be built in the Westland region of the Netherlands in the mid-19th century. The addition of sand to bogs and clay soil created fertile soil for agriculture, and around 1850, grapes were grown in the first greenhouses, simple glass constructions with one of the sides consisting of a solid wall. By the early 20th century, greenhouses began to be constructed with all sides built using glass, and they began to be heated. This also allowed for the production of fruits and vegetables that did not ordinarily grow in the area. Today, the Westland and the area around Aalsmeer have the highest concentration of greenhouse agriculture in the world. The Westland produces mostly vegetables, besides plants and flowers; Aalsmeer is noted mainly for the production of flowers and potted plants. Since the 20th century, the area around Venlo and parts of Drenthe have also become important regions for greenhouse agriculture. Since 2000, technical innovations have included the "closed greenhouse", a completely closed system allowing the grower complete control over the growing process while using less energy. Floating greenhouses are used in watery areas of the country. The Netherlands has around 4,000 greenhouse enterprises that operate over 9,000 hectares of greenhouses and employ some 150,000 workers, producing €7.2 billion worth of vegetables, fruit, plants, and flowers, some 80% of which is exported.
== See also ==
== Citations ==
== General and cited references == Cunningham, Anne S. (2000). Crystal palaces: garden conservatories of the United States. Princeton Architectural Press, New York, ISBN 1-56898-242-9 Francesco Pona: Il Paradiso de' Fiori overo Lo archetipo de' Giardini, 1622 Angelo Tamo, Verona (a manual of gardening with use greenhouse for make Giardino all'italiana) Pevsner, Nikolaus. A History of Building Types, Thames and Hudson, 1976 (1984 ed.), ISBN 0500271747. Valera, D. L.; Belmonte, L.J.; Molina, F.D.; López, A. (2016). Greenhouse agriculture in Almería. A comprehensive techno-economic analysis. Ed. Cajamar Caja Rural. 408pp. van de Muijzenberg, Erwin W B (1980). A History of Greenhousesn. Wageningen, Netherlands: Institute for Agricultural Engineering. OCLC 7164418. Vleeschouwer, Olivier de (2001). Greenhouses and conservatories. Flammarion, Paris, ISBN 2-08-010585-X. Woods, May; Warren, Arete Swartz (1988). Glass houses: history of greenhouses, orangeries and conservatories. London: Aurum Press. ISBN 978-0-906053-85-0. OCLC 17108422.
== Further reading ==
== External links == Media related to Greenhouses at Wikimedia Commons "Greenhouse". Merriam-Webster.com Dictionary. Merriam-Webster. OCLC 1032680871.