A greenhouse (also called a glasshouse, or, if with sufficient heating, a hothouse) is a structure with walls and roof made chiefly of
transparent
Transparency, transparence or transparent most often refer to:
* Transparency (optics), the physical property of allowing the transmission of light through a material
They may also refer to:
Literal uses
* Transparency (photography), a still, ...
material, such as glass, in which
plant
Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclu ...
s requiring regulated climatic conditions are grown.These structures range in size from small sheds to industrial-sized buildings. A miniature greenhouse is known as a
cold frame
In agriculture and gardening, a cold frame is a transparent-roofed enclosure, built low to the ground, used to protect plants from adverse weather, primarily excessive cold or wet. The transparent top admits sunlight and prevents heat escape via co ...
. The interior of a greenhouse exposed to sunlight becomes significantly warmer than the external temperature, protecting its contents in cold weather.
![TomateJungpflanzenAnzuchtNiederlande](https://upload.wikimedia.org/wikipedia/commons/c/c7/TomateJungpflanzenAnzuchtNiederlande.jpg)
Many commercial glass greenhouses or hothouses are
high tech
High technology (high tech), also known as advanced technology (advanced tech) or exotechnology, is technology that is at the cutting edge: the highest form of technology available. It can be defined as either the most complex or the newest te ...
production facilities for vegetables, flowers or fruits. The glass greenhouses are filled with equipment including screening installations, heating, cooling, and lighting, and may be controlled by a computer to optimize conditions for plant growth. Different techniques are then used to manage growing conditions, including air temperature,
relative humidity
Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation, dew, or fog to be present.
Humidity dep ...
and
vapour-pressure deficit
Vapour-pressure deficit, or VPD, is the difference (deficit) between the amount of moisture in the air and how much moisture the air can hold when it is saturated. Once air becomes saturated, water will condense out to form clouds, dew or films o ...
, in order to provide the optimum environment for cultivation of a specific crop.
History
![Central City Park, hothouse, circa 1877 - DPLA - 64ba00c11210fef2d3cbc4f4039859cb](https://upload.wikimedia.org/wikipedia/commons/e/e5/Central_City_Park%2C_hothouse%2C_circa_1877_-_DPLA_-_64ba00c11210fef2d3cbc4f4039859cb.jpeg)
The idea of growing plants in environmentally controlled areas has existed since
Roman
Roman or Romans most often refers to:
*Rome, the capital city of Italy
*Ancient Rome, Roman civilization from 8th century BC to 5th century AD
*Roman people, the people of ancient Rome
*'' Epistle to the Romans'', shortened to ''Romans'', a lette ...
times. The Roman emperor
Tiberius
Tiberius Julius Caesar Augustus (; 16 November 42 BC – 16 March AD 37) was the second Roman emperor. He reigned from AD 14 until 37, succeeding his stepfather, the first Roman emperor Augustus. Tiberius was born in Rome in 42 BC. His father ...
ate a
cucumber-like vegetable daily. The Roman gardeners used artificial methods (similar to the greenhouse system) of growing to have it available for his table every day of the year.
Cucumbers were planted in wheeled carts which were put in the sun daily, then taken inside to keep them warm at night. The cucumbers were stored under frames or in cucumber houses glazed with either oiled cloth known as ''specularia'' or with sheets of
selenite (a.k.a. ''lapis specularis''), according to the description by
Pliny the Elder
Gaius Plinius Secundus (AD 23/2479), called Pliny the Elder (), was a Roman author, naturalist and natural philosopher, and naval and army commander of the early Roman Empire, and a friend of the emperor Vespasian. He wrote the encyclopedic ' ...
.
The first description of a heated greenhouse is from the ''
Sanga Yorok
''Sanga Yorok'' (hangul:산가요록, hanja:山家要錄) is a Korean cook book written in hanja in about 1459 by the royal family doctor, Jeon soon. The work also incorporates descriptions of farming. The terminology means "records for farming vil ...
'', a treatise on husbandry compiled by a royal physician of the
Joseon dynasty of Korea during the 1450s, in its chapter on cultivating vegetables during winter. The treatise contains detailed instructions on constructing a greenhouse that is capable of cultivating vegetables, forcing flowers, and ripening fruit within an artificially heated environment, by utilizing ''
ondol
Ondol (; , Hangul: 온돌, 溫堗, ) or gudeul (Hangul: 구들, ) in Korean traditional architecture, is underfloor heating that uses direct heat transfer from wood smoke to heat the underside of a thick masonry floor. In modern usage it refers ...
'', the traditional Korean underfloor heating system, to maintain heat and humidity;
cob walls to retain heat; and semi-transparent oiled ''
hanji'' windows to permit light penetration for plant growth and provide protection from the outside environment. The
Annals of the Joseon Dynasty
The ''Veritable Records of the Joseon Dynasty'' (also known as the ''Annals of the Joseon Dynasty'' or the ''True Record of the Joseon Dynasty''; ko, 조선왕조실록 and ) are the annual records of Joseon, the last royal house to rule K ...
confirm that greenhouse-like structures incorporating ''ondol'' were constructed to provide heat for
mandarin orange
The mandarin orange (''Citrus reticulata''), also known as the mandarin or mandarine, is a small citrus tree fruit. Treated as a distinct species of orange, it is usually eaten plain or in fruit salads. Tangerines are a group of orange-colou ...
trees during the winter of 1438.
The concept of greenhouses also appeared in the
Netherlands
)
, anthem = ( en, "William of Nassau")
, image_map =
, map_caption =
, subdivision_type = Sovereign state
, subdivision_name = Kingdom of the Netherlands
, established_title = Before independence
, established_date = Spanish Netherl ...
and then
England
England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe b ...
in the 17th century, along with the plants. Some of these early attempts required enormous amounts of work to close up at night or to winterize. There were serious problems with providing adequate and balanced heat in these early greenhouses. The first 'stove' (heated) greenhouse in the UK was completed at
Chelsea Physic Garden
The Chelsea Physic Garden was established as the Apothecaries' Garden in London, England, in 1673 by the Worshipful Society of Apothecaries to grow plants to be used as medicines. This four acre physic garden, the term here referring to the sc ...
by 1681. Today, the
Netherlands
)
, anthem = ( en, "William of Nassau")
, image_map =
, map_caption =
, subdivision_type = Sovereign state
, subdivision_name = Kingdom of the Netherlands
, established_title = Before independence
, established_date = Spanish Netherl ...
has many of the largest greenhouses in the world, some of them so vast that they are able to produce millions of vegetables every year.
Experimentation with greenhouse design continued during the 17th century in Europe, as technology produced better glass and construction techniques improved. The greenhouse at the
Palace of Versailles was an example of their size and elaborateness; it was more than long, wide, and high.
The French botanist
Charles Lucien Bonaparte is often credited with building the first practical modern greenhouse in
Leiden
Leiden (; in English and archaic Dutch also Leyden) is a city and municipality in the province of South Holland, Netherlands. The municipality of Leiden has a population of 119,713, but the city forms one densely connected agglomeration wi ...
, Holland, during the 1800s to grow medicinal tropical plants.
Originally only on the estates of the rich, the growth of the science of
botany
Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the Ancient Greek w ...
caused greenhouses to spread to the universities. The French called their first greenhouses ''
orangeries
An orangery or orangerie was a room or a dedicated building on the grounds of fashionable residences of Northern Europe from the 17th to the 19th centuries where orange and other fruit trees were protected during the winter, as a very large ...
'', since they were used to protect orange trees from freezing. As pineapples became popular, ''pineries'', or
pineapple pits, were built.
19th century
The golden era of the greenhouse was in England during the Victorian era, where the largest glasshouses yet conceived were constructed; ones with sufficient height for sizeable trees were often called
palm houses. These were normally in public gardens and parks. These were a stage in the 19th-century development of glass and iron architecture, which was also widely used in railway stations, markets, exhibition halls, and other large buildings needing a large and open internal area. One of the earliest examples of a palm house is in the
Belfast Botanic Gardens
Botanic Gardens is a public garden in Belfast, Northern Ireland.
Occupying of south Belfast, the gardens are popular with office workers, students and tourists. They are located on Stranmillis Road in Queen's Quarter, with Queen's Univers ...
. Designed by
Charles Lanyon
Sir Charles Lanyon DL, JP (6 January 1813 – 31 May 1889) was an English architect of the 19th century. His work is most closely associated with Belfast, Northern Ireland.
Biography
Lanyon was born in Eastbourne, Sussex (now East Sussex) in ...
, the building was completed in 1840. It was constructed by iron-maker
Richard Turner, who would later build the
Palm House, Kew Gardens
The Palm House is a large palm house in the Royal Botanic Gardens, Kew, in London, that specialises in growing palms and other tropical and subtropical plants. It was completed in 1848. Many of its plants are endangered or extinct in the wild. ...
at the
Royal Botanic Gardens, Kew
Royal Botanic Gardens, Kew is a non-departmental public body in the United Kingdom sponsored by the Department for Environment, Food and Rural Affairs. An internationally important botanical research and education institution, it employs 1,10 ...
, London, in 1848. This came shortly after the
Chatsworth Great Conservatory (1837-40) and shortly before
The Crystal Palace
The Crystal Palace was a cast iron and plate glass structure, originally built in Hyde Park, London, to house the Great Exhibition of 1851. The exhibition took place from 1 May to 15 October 1851, and more than 14,000 exhibitors from around th ...
(1851), both designed by
Joseph Paxton, and both now lost.
Other large greenhouses built in the 19th century included the
New York Crystal Palace
New York Crystal Palace was an exhibition building constructed for the Exhibition of the Industry of All Nations in New York City in 1853, which was under the presidency of the mayor Jacob Aaron Westervelt. The building stood in Reservoir Squar ...
,
Munich
Munich ( ; german: München ; bar, Minga ) is the capital and most populous city of the German state of Bavaria. With a population of 1,558,395 inhabitants as of 31 July 2020, it is the third-largest city in Germany, after Berlin and Ha ...
’s
Glaspalast and the
Royal Greenhouses of Laeken
The Royal Greenhouses of Laeken (french: Serres Royales de Laeken, nl, Koninklijke Serres van Laken) are a vast complex of monumental heated greenhouses in the park of the Royal Palace of Laeken (northern part of the City of Brussels), Belgium ...
(1874–1895) for
King Leopold II of Belgium
* german: link=no, Leopold Ludwig Philipp Maria Viktor
, house = Saxe-Coburg and Gotha
, father = Leopold I of Belgium
, mother = Louise of Orléans
, birth_date =
, birth_place = Brussels, Belgium
, death_date = ...
. In Japan, the first greenhouse was built in 1880 by
Samuel Cocking, a British merchant who exported
herbs.
20th century
In the 20th century, the
geodesic dome
A geodesic dome is a hemispherical thin-shell structure (lattice-shell) based on a geodesic polyhedron. The triangular elements of the dome are structurally rigid and distribute the structural stress throughout the structure, making geodesic do ...
was added to the many types of greenhouses. Notable examples are the
Eden Project
The Eden Project ( kw, Edenva) is a visitor attraction in Cornwall, England, UK. The project is located in a reclaimed china clay pit, located from the town of St Blazey and from the larger town of St Austell.Ordnance Survey (2005). ''OS ...
in
Cornwall
Cornwall (; kw, Kernow ) is a historic county and ceremonial county in South West England. It is recognised as one of the Celtic nations, and is the homeland of the Cornish people. Cornwall is bordered to the north and west by the Atlantic ...
,
The Rodale Institute
Rodale Institute is a non-profit organization that supports research into organic farming. It was founded in Emmaus, Pennsylvania in 1947 by J. I. Rodale, an organic living entrepreneur. After J.I. Rodale died in 1971, his son Robert Rodale purcha ...
in Pennsylvania, the
Climatron
The Climatron is a greenhouse enclosed in a geodesic dome that is part of the Missouri Botanical Garden in St. Louis. Initiated by then Garden director Frits W. Went, the dome is the world's first completely air-conditioned greenhouse and the f ...
at the
Missouri Botanical Garden
The Missouri Botanical Garden is a botanical garden located at 4344 Shaw Boulevard in St. Louis, Missouri. It is also known informally as Shaw's Garden for founder and philanthropist Henry Shaw. Its herbarium, with more than 6.6 million ...
in St. Louis, Missouri, and
Toyota Motor Manufacturing Kentucky
Toyota Motor Manufacturing Kentucky (TMMK) is an automobile manufacturing factory in Georgetown, Kentucky, United States. It is a subsidiary of Toyota Motor North America, itself a subsidiary of Toyota Motor Corporation of Japan. The plant assem ...
. The pyramid is another popular shape for large, high greenhouses; there are several pyramidal greenhouses at the
Muttart Conservatory
The Muttart Conservatory () is a botanical garden located in the North Saskatchewan river valley, across from the downtown core in Edmonton, Alberta, Canada. One of the best-known landmarks of Edmonton, the conservatory consists of three city-o ...
in
Alberta
Alberta ( ) is one of the thirteen provinces and territories of Canada. It is part of Western Canada and is one of the three prairie provinces. Alberta is bordered by British Columbia to the west, Saskatchewan to the east, the Northwest Ter ...
(c, 1976).
Greenhouse structures adapted in the 1960s when wider sheets of
polyethylene
Polyethylene or polythene (abbreviated PE; IUPAC name polyethene or poly(methylene)) is the most commonly produced plastic. It is a polymer, primarily used for packaging ( plastic bags, plastic films, geomembranes and containers including b ...
(polythene) film became widely available.
Hoop houses were made by several companies and were also frequently made by the growers themselves. Constructed of aluminum extrusions, special galvanized steel tubing, or even just lengths of steel or PVC water pipe, construction costs were greatly reduced. This resulted in many more greenhouses being constructed on smaller farms and garden centers. Polyethylene film durability increased greatly when more effective UV-inhibitors were developed and added in the 1970s; these extended the usable life of the film from one or two years up to three and eventually four or more years.
Gutter-connected greenhouses became more prevalent in the 1980s and 1990s. These greenhouses have two or more bays connected by a common wall, or row of support posts. Heating inputs were reduced as the ratio of floor area to exterior wall area was increased substantially. Gutter-connected greenhouses are now commonly used both in production and in situations where plants are grown and sold to the public as well. Gutter-connected greenhouses are commonly covered with structured polycarbonate materials, or a double layer of polyethylene film with air blown between to provide increased heating efficiencies.
Theory of operation
The warmer temperature in a greenhouse occurs because incident
solar radiation
Solar irradiance is the power per unit area (surface power density) received from the Sun in the form of electromagnetic radiation in the wavelength range of the measuring instrument.
Solar irradiance is measured in watts per square metre ( ...
passes through the transparent roof and walls and is absorbed by the floor, earth, and contents, which become warmer. As the structure is not open to the atmosphere, the warmed air cannot escape via
convection
Convection is single or multiphase fluid flow that occurs spontaneously due to the combined effects of material property heterogeneity and body forces on a fluid, most commonly density and gravity (see buoyancy). When the cause of the conve ...
, so the temperature inside the greenhouse rises.
This differs from the earth-oriented theory known as the "
greenhouse effect
The greenhouse effect is a process that occurs when energy from a planet's host star goes through the planet's atmosphere and heats the planet's surface, but greenhouse gases in the atmosphere prevent some of the heat from returning directly ...
",, which is a reduction in a planet's heat loss through radiation.
Quantitative studies suggest that the effect of infrared radiative cooling is not negligibly small, and may have economic implications in a heated greenhouse. Analysis of issues of near-infrared radiation in a greenhouse with screens of a high coefficient of reflection concluded that installation of such screens reduced heat demand by about 8%, and application of dyes to transparent surfaces was suggested. Composite less-reflective glass, or less effective but cheaper anti-reflective coated simple glass, also produced savings.
Ventilation
Ventilation
Ventilation may refer to:
* Ventilation (physiology), the movement of air between the environment and the lungs via inhalation and exhalation
** Mechanical ventilation, in medicine, using artificial methods to assist breathing
*** Ventilator, a m ...
is one of the most important components in a successful greenhouse. If there is no proper ventilation, greenhouses and their growing plants can become prone to problems. The main purposes of ventilation is to regulate the temperature and humidity to the optimal level, and to ensure movement of air and thus prevent the build-up of plant pathogens (such as ''
Botrytis cinerea
''Botrytis cinerea'' is a necrotrophic fungus that affects many plant species, although its most notable hosts may be wine grapes. In viticulture, it is commonly known as "botrytis bunch rot"; in horticulture, it is usually called "grey mould" o ...
'') that prefer still air conditions. Ventilation also ensures a supply of fresh air for photosynthesis and plant
respiration
Respiration may refer to:
Biology
* Cellular respiration, the process in which nutrients are converted into useful energy in a cell
** Anaerobic respiration, cellular respiration without oxygen
** Maintenance respiration, the amount of cellul ...
, and may enable important
pollinators
A pollinator is an animal that moves pollen from the male anther of a flower to the female stigma of a flower. This helps to bring about fertilization of the ovules in the flower by the male gametes from the pollen grains.
Insects are the maj ...
to access the greenhouse crop.
![Central City Park, hothouse interior, circa 1877 - DPLA - c4a22591a2b28b6ccf7b4c4bd3a4af1e](https://upload.wikimedia.org/wikipedia/commons/0/07/Central_City_Park%2C_hothouse_interior%2C_circa_1877_-_DPLA_-_c4a22591a2b28b6ccf7b4c4bd3a4af1e.jpeg)
Ventilation can be achieved via the use of vents – often controlled automatically via a computer – and recirculation fans.
Heating
Heating
A central heating system provides warmth to a number of spaces within a building from one main source of heat. It is a component of heating, ventilation, and air conditioning (short: HVAC) systems, which can both cool and warm interior spaces.
...
or
electricity
Electricity is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as describ ...
is one of the most considerable costs in the operation of greenhouses across the globe, especially in colder climates. The main problem with heating a greenhouse as opposed to a building that has solid
opaque
Opacity or opaque may refer to:
* Impediments to (especially, visible) light:
** Opacities, absorption coefficients
** Opacity (optics), property or degree of blocking the transmission of light
* Metaphors derived from literal optics:
** In lingu ...
walls is the amount of heat lost through the greenhouse covering. Since the coverings need to allow light to filter into the structure, they conversely cannot insulate very well. With traditional plastic greenhouse coverings having an
R-value of around 2, a great amount of money is therefore spent to continually replace the heat lost. Most greenhouses, when supplemental heat is needed use natural gas or
electric furnaces.
Passive heating methods exist which seek heat using low energy input.
Solar energy can be captured from periods of relative abundance (day time/summer), and released to boost the temperature during cooler periods (night time/winter).
Waste heat
Waste heat is heat that is produced by a machine, or other process that uses energy, as a byproduct of doing work. All such processes give off some waste heat as a fundamental result of the laws of thermodynamics. Waste heat has lower utility ...
from livestock can also be used to heat greenhouses, e.g., placing a chicken coop inside a greenhouse recovers the heat generated by the chickens, which would otherwise be wasted. Some greenhouses also rely on
geothermal heating
Geothermal heating is the direct use of geothermal energy for some heating applications. Humans have taken advantage of geothermal heat this way since the Paleolithic era. Approximately seventy countries made direct use of a total of 270 PJ of ...
.
Cooling
Cooling is typically done by opening windows in the greenhouse when it gets too warm for the plants inside it. This can be done manually, or in an automated manner. Window actuators can open windows due to temperature difference or can be opened by
electronic
Electronic may refer to:
*Electronics, the science of how to control electric energy in semiconductor
* ''Electronics'' (magazine), a defunct American trade journal
*Electronic storage, the storage of data using an electronic device
*Electronic co ...
controllers. Electronic controllers are often used to monitor the temperature and adjusts the furnace operation to the conditions. This can be as simple as a basic thermostat, but can be more complicated in larger greenhouse operations.
For very hot situations, a
shade house A shade house is a horticultural structure which provides a mix of shade and light to provide suitable conditions for shade-loving plants, or to reduce the temperatures under the cover. Typically it will have a frame which supports mesh fabric or ...
providing cooling by shade may be used.
Lighting
During the day, light enters the greenhouse via the windows and is used by the plants. Some greenhouses are also equipped with
grow light
A grow light is an electric light to help plants grow. Grow lights either attempt to provide a light spectrum similar to that of the sun, or to provide a spectrum that is more tailored to the needs of the plants being cultivated (typically a varyi ...
s (often LED lights) which are switched on at night to increase the amount of light the plants get, hereby increasing the yield with certain crops.
Carbon dioxide enrichment
The benefits of
carbon dioxide
Carbon dioxide ( chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is trans ...
enrichment to about 1100 parts per million in greenhouse cultivation to enhance plant growth has been known for nearly 100 years. After the development of equipment for the controlled serial enrichment of carbon dioxide, the technique was established on a broad scale in the Netherlands. Secondary metabolites, e.g., cardiac glycosides in ''
Digitalis lanata
''Digitalis lanata'', vernacularly often called woolly foxglove or Grecian foxglove, is a species of foxglove, a flowering plant in the plantain family Plantaginaceae. It gets its name due to the woolly indumentum of the leaves. ''D. lanata'', l ...
'', are produced in higher amounts by greenhouse cultivation at enhanced temperature and at enhanced carbon dioxide concentration. Carbon dioxide enrichment can also reduce greenhouse water usage by a significant fraction by mitigating the total air-flow needed to supply adequate carbon for plant growth and thereby reducing the quantity of water lost to evaporation. Commercial greenhouses are now frequently located near appropriate industrial facilities for mutual benefit. For example, Cornerways Nursery in the UK is strategically placed near a major sugar refinery, consuming both waste heat and CO
2 from the refinery which would otherwise be vented to atmosphere. The refinery reduces its carbon emissions, whilst the nursery enjoys boosted tomato yields and does not need to provide its own greenhouse heating.
Enrichment only becomes effective where, by
Liebig's law, carbon dioxide has become the
limiting factor
A limiting factor is a variable of a system that causes a noticeable change in output or another measure of a type of system. The limiting factor is in a pyramid shape of organisms going up from the producers to consumers and so on. A factor not l ...
. In a controlled greenhouse,
irrigation
Irrigation (also referred to as watering) is the practice of applying controlled amounts of water to land to help grow crops, landscape plants, and lawns. Irrigation has been a key aspect of agriculture for over 5,000 years and has been devel ...
may be trivial, and soils may be
fertile by default. In less-controlled gardens and open fields,
rising CO2 levels only increase
primary production
In ecology, primary production is the synthesis of organic compounds from atmospheric or aqueous carbon dioxide. It principally occurs through the process of photosynthesis, which uses light as its source of energy, but it also occurs through ...
to the point of soil depletion (assuming no droughts, flooding, or both), as demonstrated ''prima facie'' by CO
2 levels continuing to rise. In addition, laboratory experiments, free air carbon enrichment (FACE) test plots, and field measurements provide
replicability
Reproducibility, also known as replicability and repeatability, is a major principle underpinning the scientific method. For the findings of a study to be reproducible means that results obtained by an experiment or an observational study or in a ...
.
Types
![Private greenhouse](https://upload.wikimedia.org/wikipedia/commons/b/b0/Private_greenhouse.jpg)
In domestic greenhouses, the glass used is typically 3mm (or ⅛″) 'horticultural glass' grade, which is good quality glass that should not contain air bubbles (which can produce scorching on leaves by acting like lenses).
Plastics mostly used are
polyethylene
Polyethylene or polythene (abbreviated PE; IUPAC name polyethene or poly(methylene)) is the most commonly produced plastic. It is a polymer, primarily used for packaging ( plastic bags, plastic films, geomembranes and containers including b ...
film and multiwall sheets of
polycarbonate material, or PMMA
acrylic glass
Poly(methyl methacrylate) (PMMA) belongs to a group of materials called engineering plastics. It is a transparent thermoplastic. PMMA is also known as acrylic, acrylic glass, as well as by the trade names and brands Crylux, Plexiglas, Acrylite ...
.
Commercial glass greenhouses are often high-tech production facilities for vegetables or flowers. The glass greenhouses are filled with equipment such as screening installations, heating, cooling and lighting, and may be automatically controlled by a computer.
Dutch Light
In the UK and other Northern European countries a pane of horticultural glass referred to as "Dutch Light" was historically used as a standard unit of construction, having dimensions of 28¾″ x 56″ (approx. 730 mm x 1422 mm). This size gives a larger glazed area when compared with using smaller panes such as the 600 mm width typically used in modern domestic designs which then require more supporting framework for a given overall greenhouse size. A style of greenhouse having sloped sides (resulting in a wider base than at eaves height) and using these panes uncut is also often referred to as of "Dutch Light design", and a
cold frame
In agriculture and gardening, a cold frame is a transparent-roofed enclosure, built low to the ground, used to protect plants from adverse weather, primarily excessive cold or wet. The transparent top admits sunlight and prevents heat escape via co ...
using a full- or half-pane as being of "Dutch" or "half-Dutch" size.
Greenhouses with spectrally selective solar modules
Uses
Greenhouses allow for greater control over the growing environment of plants. Depending upon the technical specification of a greenhouse, key factors which may be controlled include temperature, levels of light and shade,
irrigation
Irrigation (also referred to as watering) is the practice of applying controlled amounts of water to land to help grow crops, landscape plants, and lawns. Irrigation has been a key aspect of agriculture for over 5,000 years and has been devel ...
,
fertilizer
A fertilizer (American English) or fertiliser (British English; see spelling differences) is any material of natural or synthetic origin that is applied to soil or to plant tissues to supply plant nutrients. Fertilizers may be distinct from ...
application, and atmospheric
humidity
Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation, dew, or fog to be present.
Humidity dep ...
. 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 house A shade house is a horticultural structure which provides a mix of shade and light to provide suitable conditions for shade-loving plants, or to reduce the temperatures under the cover. Typically it will have a frame which supports mesh fabric or ...
s 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
Almería (, , ) is a city and municipality of Spain, located in Andalusia. It is the capital of the province of the same name. It lies on southeastern Iberia on the Mediterranean Sea. Caliph Abd al-Rahman III founded the city in 955. The city g ...
,
Andalucía,
Spain
, image_flag = Bandera de España.svg
, image_coat = Escudo de España (mazonado).svg
, national_motto = ''Plus ultra'' (Latin)(English: "Further Beyond")
, national_anthem = (English: "Royal March")
, i ...
, where greenhouses cover almost .
Greenhouses are often used for growing
flowers
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechanism ...
,
vegetable
Vegetables are parts of plants that are consumed by humans or other animals as food. The original meaning is still commonly used and is applied to plants collectively to refer to all edible plant matter, including the flowers, fruits, stems, ...
s,
fruit
In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering.
Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in particu ...
s, 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
Hydroponics is a type of horticulture and a subset of hydroculture which involves growing plants, usually crops or medicinal plants, without soil, by using water-based mineral nutrient solutions in aqueous solvents. Terrestrial or aquatic plant ...
(especially hydroponic
A-frame
An A-frame is a basic structure designed to bear a load in a lightweight economical manner. The simplest form of an A-frame is two similarly sized beams, arranged in an angle of 45 degrees or less, attached at the top, like an uppercase lette ...
s) can be used to make the most use of the interior space when growing crops to mature size inside the greenhouse.
Bumblebee
A bumblebee (or bumble bee, bumble-bee, or humble-bee) is any of over 250 species in the genus ''Bombus'', part of Apidae, one of the bee families. This genus is the only extant group in the tribe Bombini, though a few extinct related genera ...
s can be used as
pollinators for
pollination
Pollination is the transfer of pollen from an anther of a plant to the stigma of a plant, later enabling fertilisation and the production of seeds, most often by an animal or by wind. Pollinating agents can be animals such as insects, birds, a ...
, but other types of
bees have also been used, as well as artificial pollination.
The relatively closed environment of a greenhouse has its own unique management requirements, compared with outdoor production.
Pests and
disease
A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that a ...
s, 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
Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled people t ...
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 trough
A parabolic trough is a type of solar thermal collector that is straight in one dimension and curved as a parabola in the other two, lined with a polished metal mirror. The sunlight which enters the mirror parallel to its plane of symmetry is foc ...
s.
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 provide protection 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.
File:Flowers in a greenhouse.jpg, Flowers in a greenhouse
File:Plastic sea, Almería Spain.jpg, Greenhouses in Almería
Almería (, , ) is a city and municipality of Spain, located in Andalusia. It is the capital of the province of the same name. It lies on southeastern Iberia on the Mediterranean Sea. Caliph Abd al-Rahman III founded the city in 955. The city g ...
as seen from space
Adoption
Worldwide, there are an estimated nine million acres of greenhouses.
Netherlands
![Westland kassen](https://upload.wikimedia.org/wikipedia/commons/2/21/Westland_kassen.jpg)
The
Netherlands
)
, anthem = ( en, "William of Nassau")
, image_map =
, map_caption =
, subdivision_type = Sovereign state
, subdivision_name = Kingdom of the Netherlands
, established_title = Before independence
, established_date = Spanish Netherl ...
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
Aalsmeer () is a municipality and a town in the Netherlands, in the province of North Holland. Its name is derived from the Dutch for eel (''aal'') and lake (''meer''). Aalsmeer is bordered by the Westeinderplassen lake, the largest open water of ...
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
Venlo () is a city and municipality in the southeastern Netherlands, close to the border with Germany. It is situated in the province of Limburg, about 50 km east of the city of Eindhoven, 65 km north east of the provincial capital Maastricht, a ...
and parts of
Drenthe have also become important regions for greenhouse agriculture.
Since 2000, technical innovations include 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
*
Bioshelter
A bioshelter is a solar greenhouse managed as an indoor ecosystem. The word bioshelter was coined by the New Alchemy Institute and solar designers Sean Wellesley-Miller and Day Chahroudi.Todd, N.J. and Todd J., 1994. From Eco-Cities to Living Mach ...
*
Biosphere 2
*
Conservatory (greenhouse)
*
Floriculture
Floriculture, or flower farming, is a branch of horticulture concerned with the cultivation of flowering and ornamental plants for gardens and for floristry, comprising the floral industry. The development of new varieties by plant breeding is ...
*
Greenhouse gas
*
High tunnel
*
IBTS Greenhouse
The IBTS (“Integrated Biotectural System")-greenhouse is a biotectural, urban development project suited for hot arid deserts. It was part of the Egyptian strategy for the afforestation of desert lands from 2011 until spring of 2015, when geopol ...
*
Phytotron
A phytotron is an enclosed research greenhouse used for studying interactions between plants and the environment. It was a product of the disciplines of plant physiology and botany.
Overview
Phytotrons unified and extended earlier piecemeal effo ...
*
Plasticulture
The term plasticulture refers to the practice of using plastic materials in agricultural applications. The plastic materials themselves are often and broadly referred to as "ag plastics". Plasticulture ag plastics include soil fumigation film, i ...
*
Row cover
In agriculture and gardening, row cover is any transparent or semi-transparent flexible material, like fabric or plastic sheeting, used as a protective covering for plants, usually vegetables. Covers are used to extend growing seasons, and redu ...
*
Seasonal thermal energy storage
Seasonal thermal energy storage (STES), also known as inter-seasonal thermal energy storage,
is the storage of heat or cold for periods of up to several months. The thermal energy can be collected whenever it is available and be used whenever nee ...
*
Seawater greenhouse
A seawater greenhouse is a greenhouse structure that enables the growth of crops and the production of fresh water in arid regions which constitute about one third of the earth's land area. This in response to the global water scarcity and peak ...
*
Tessellated roof
*
Vertical farming
Vertical farming is the practice of growing crops in vertically stacked layers. It often incorporates controlled-environment agriculture, which aims to optimize plant growth, and soilless farming techniques such as hydroponics, aquaponics, and ae ...
*
Winter garden
A winter garden is a kind of garden maintained in wintertime.
History
The origin of the winter garden dates back to the 17th to 19th centuries where European nobility would construct large conservatories that would house tropical and subtro ...
Citations
General and cited references
* Cunningham, Anne S. (2000)
''Crystal palaces: garden conservatories of the United States'' Princeton Architectural Press, New York,
*
Francesco Pona
Francesco Pona (1595–1655) was an Italian medical doctor, philosopher, Marinist poet and writer from Verona, whose works ranged from scientific treatises and history to poetry and plays.
Biography
A Veronese medical doctor and member of ma ...
: ''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
The Italian garden (or giardino all'italiana () is best known for a number of large Italian Renaissance gardens which have survived in something like their original form. In the history of gardening, during the Renaissance, Italy had the most ...
)
*
Pevsner, Nikolaus
Sir Nikolaus Bernhard Leon Pevsner (30 January 1902 – 18 August 1983) was a German-British art historian and architectural historian best known for his monumental 46-volume series of county-by-county guides, ''The Buildings of England'' (1 ...
. ''A History of Building Types'',
Thames and Hudson
Thames & Hudson (sometimes T&H for brevity) is a publisher of illustrated books in all visually creative categories: art, architecture, design, photography, fashion, film, and the performing arts. It also publishes books on archaeology, history, ...
, 1976 (1984 ed.), .
* 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.
*
* Vleeschouwer, Olivier de (2001)
''Greenhouses and conservatories'' Flammarion, Paris, .
*
Further reading
*
*
External links
*
{{Authority control
Agricultural buildings
Garden features
Horticulture