ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

Greenhouse Design

Updated on September 20, 2010

It is estimated that there are more than 1500000 greenhouses in great Britain. Some may be used mainly as potting sheds and tool shelters, but there can be few that do not at sometime shelter plant ‘immigrants’ that are unable to withstand the British winter. Apart from conservatories, the main types of greenhouse are cold house, which is unheated except perhaps for soil warming equipment; the cold house, where are temperature of atleast 40°F is always maintained.

The average beginner will start with a simple cold frame or green house, with which a good deal can be done. Apart from protecting tender plants from frost and snow, one can raise in them, seeds early in the year and perhaps grow a few exotic plants that would not survive in open.

The more advanced gardener, however, will undoubtedly want some form of heating and this can always be added to a coldhouse if it is weatherproof. As a rule it is advisable to buy a greenhouse in sections. Not only is this type quick and easy to erect but in the long run it is likely to prove more satisfactory than an amateur built structure. Manufacturers provide detailed literature, and there is a variety of shapes, sizes and materials.

span roof house
span roof house
three quarter span house
three quarter span house


The traditional style is the span roof house, fitted with staging along two sides and a path in the middle. This design is very suitable for a large, open plot with full sunshine.

For a more restricted site, the three quarter span house is useful. One can utilize a house wall for the rear side, as in the diagram, or buy a self contained house with a wooden rear wall. It can have a single line of staging on one side and tiered staging against the wall.

The cheapest form of greenhouse is the lean-to, which also fixes against a wall. This is a good buy for a small garden; it is neat and space-saving, and the large roof area attracts plenty of light, while a brick rear wall tends to retain warmth.

Lean-to greenhouse
Lean-to greenhouse

Modern greenhouses are made in materials including wood, aluminum, steel, brick, and concrete. Most amateurs will chose either an all-metal type, which needs no painting, or an all-wood type, which is cheaper and also tends to retain warmth longer.

Gardeners fortunate enough to be able to obtain farm or stable manure can provide their cold house with a valuable source of heat under the soil beds, as well as a rich plant diet (excellent for early salads). The cold house is useful in winter for semi dormant plants, and for such spring flowers as daffodils, hyacinths, tulips and scillas. Some food crops such -- e.g. rhubarb, seakale, chichory -- can be forced in it, and as spring arrives the early seed sowing can be done under glass weeks ahead of outdoor sowings.


A house used especially for propagating in late winter needs as much sunlight as possible. The design affects the amount of light admitted, and it has been found that if the roof slopes at 30° to the horizontal, this allows the maximum amount of light to enter the minimum loss by reflection from glass. A number of houses are constructed to this design.

In the larger garden, the key to success is the service corner. Here the tender plants can be protected during winter and the half hardy annuals and vegetables raised from seeds before being planted out in their permanent quarters. For convenience in working the potting shed with its supply of soils, the green house and the frames should all be located close together, and it will be a great advantage to have a water supply available on the site.


Galvanized steel and aluminum green houses need no maintenance of any kind. They are easy to assemble and being sectional can be extended when required. The wooden staging can be taken out when the house is wanted for tomatoes, etc.


Traditional wooden greenhouse with red cedar cladding. Only the framing needs painting, though the cedar wood benefits by treatment with a water repellent preservative. This house is made in various sizes, and the main sections are interchangeable to suit different sizes. Note the neat gutter and down pipe supplying a water butt.

Adding Warmth

A cold greenhouse rarely satisfied for long: even the beginner soon starts to consider the heating apparatus. There are still many greenhouses heated by coke stove with a hot water boiler feeding cast iron pipes -- many commercial growers prefer this system because it is never subject to power cuts!

 

When a hot water system is being installed, do not try to economize bye reducing the length of the piping to be fitted. Best results are obtained from large areas of low temperature pipes; excessive heat makes the atmosphere too dry. Also, stoking it easier with extensive piping as the larger quantity of water retains it heat much longer. Normally, stoking such as system will be necessary two or three times a day.

paraffin oil heater
paraffin oil heater

A small greenhouse can also be heated economically by a paraffin oil heater. Special models are made for greenhouse use which are fitted with water troughs to maintain atmospheric humidity, which will burn for upwards of 48 hours without attention. These need little attention, but wicks should be regularly inspected and trimmed, and cleanliness of both the appliance and fuel is important.

While such a heater is all that many gardeners need, others are turning increasingly to gas or electrical installations. Both gas and electricity supply authorities provide a wide range of greenhouse aids that are worth studying before an order is placed. Both, for example, offer heat controlled by thermostat so that the gardener is not tied so much to his greenhouse. Electric greenhouse heaters, usually take the form of aluminum tubular units which can be built up in tiers on the walls or floor; there should be same number of units on either side of the house to ensure even heat distribution. Another type of heater is water filled to permit gradual adjustment of temperature after the thermostat has operated.

An advantage of using electricity, ofcourse, is that once a power supply has been brought into the greenhouse it becomes possible to install electric soil warmers, ventilators, soil sterilizers and so on. At the same time, one must remember that the cost of heating greenhouse by electricity rises rapidly as the temperature is raised. For instance, it costs more than twice as much to maintain a house at 50°F as it does at 45°F, and more than three times as much to maintain 55°F.

Electric digital Thermostat
Electric digital Thermostat
Electrical heater
Electrical heater

Thermostatic heating control not only ensures an even temperature but keeps down running costs. The type shown is made from steel and is extremely sturdy and very stable on the ground. It has a digital screen which eases the process to control temperature. The fan with this thermostat is really incredible giving smooth and gentle air circulation and the heat that emerges is a gentle heat to avoid scorching nearby plants.

greenhouse ventilation
greenhouse ventilation

Ventilation

Top ventilation is most essential of all types. Wherever possible the ventilators should be on both sides of greenhouse so that opening can be adjusted according to the wind. Always ventilate with a rising temperature and never allow the thermometer to stand too high before air is given, thus causing a sudden drop. Side ventilation is only used in summer weather when it cannot cause a draught. Always close the house early, particularly during the duller months, so as to shut some of the suns warmth into the house to maintain a genial atmosphere during the night. This applies to both types of ventilators.

Staging

The interior part of the greenhouse should be settled in conjunction with ventilating arrangement and type of heating apparatus. Shelves should be arranged so that water will not drip on to plant below. The path should be no more than the width of the door (usually 2 ft 6 in.) staging made of slatted wood to allow free circulation of air around the plants is most often used. Solid staging of sheet zinc, etc., supported on wooden framework, are often used in conservatories. These must be covered with coarse sand, washed pebbles or clean small clinkers. This last has the advantage of conserving moisture and during the annual cleaning can be washed in a sieve. When adopting this method, the edge of staging can be clothed with tradescantia or helxine rooted in ribbon of soil.

 During the early spring the house is often crowded with annuals and vegetables for first crops being raised. An extra temporary shelf can be made from wooden planks slipped into supports fixed to the roof.

soil warming cable
soil warming cable

Easy Soil Heating

A popular method is to heat a soil bed in one corner of the greenhouse, or a bed in an outside frame, by means of soil warming cables. This allows tender seedlings to be raised, cuttings taken, etc., at low cost. A similar cable will provide bottom heat for a deep seed box, and the box can be fitted with a plastic dome or tent cover which gives headroom for larger plants. The mains attached by clips to the frame walls, or laid on 2 in. of washed sand and covered with a further 2-3 in. Pots and pans are stood on this sand bed, and granulated peat is packed around them to conserve the heat.

Mist Propagation

A recent development in greenhouse aids is this system of propagating cuttings. It is claimed that 95% success with cuttings become quite normal with the system, easy subjects taking root more quickly and difficult ones more certainly. The idea is that the cuttings are never allowed to flag; after planting in the rooting medium they receive a spray of fine water mist whenever they would otherwise begin to dry off. The spray nozzle can be seen mounted above the cuttings, which are in electrically warmed soil. In the corner is a humidity sensitive detector which turns on the water when the atmosphere becomes dry. Water from the fine mist spray then envelops the foliage of the cuttings until the humidity detector unit operates and automatically switches off the spray.


automatic drip feed system
automatic drip feed system
capillary mat watering system
capillary mat watering system

Watering

Working on the principle that greenhouse plants need water only in small amounts but often, manufacturers now market some ingenious automatic watering systems.

The drawing shows an automatic drip feed system which is connected to a convenient tap. Water is released through drip nozzles in a flexible irrigation line at intervals.

A variety of techniques of capillary watering is now used in equally in the greenhouse and nursery industry.  One of these techniques entails using line-source tubes which would take water to a capillary mat.  Water would then travel through the mat by capillary action pretty much like a sponge.  Containers are positioned on top of a saturated mat, which permits the medium in the container to soak up water.  Containers must be saturated before being placed on capillary mat systems to guarantee successful water consumption.  Capillary mat irrigation systems can use 60% less water than overhead irrigation systems.  Capillary mats have the limitation as other sub-irrigation types in that salts can build up in substrate over time without periodic leaching events.


Pest Control

Pests under glass are a special problem. With this device, small tablets are placed in a non illuminating glass bulb which is then plugged into a lampholder. When the lamp is switched on, it melts and vaporizes the tablets. This vapor spreads through the greenhouse, dealing with aphides, red spider and white flies.

Automatic Pesticide sprayers ensures consistent, prompt and effective treatment against pests. These also allow biological control to be carried out without the use of pesticide, resulting in a significant financial saving

Comments

    0 of 8192 characters used
    Post Comment

    • FuzzyCookie profile imageAUTHOR

      FuzzyCookie 

      7 years ago

      Hi Wife Who Saves, thank you for the compliment :)

    • profile image

      Wife Who Saves 

      7 years ago

      This is the most comprehensive hub I have read on greenhouse design. Rated up and awesome.

    • FuzzyCookie profile imageAUTHOR

      FuzzyCookie 

      7 years ago

      Thank you equebee, for your wonderful comment. I am glad to know that this hub has proved to be useful to you. :)

    • equebee profile image

      equebee 

      7 years ago from Lincoln

      As an amateur gardener, I found this Hub was very informative, and much easier than ploughing through a gardening book to find out information about growing seedlings and plants in a greenhouse.

      Excellent Fuzzy

    • FuzzyCookie profile imageAUTHOR

      FuzzyCookie 

      7 years ago

      hi Alternative Prime, I am glad that information provided here has been useful to you :)

    • Alternative Prime profile image

      Alternative Prime 

      7 years ago from > California

      Great Hub Fuzzy,

      Very interesting & informative. Almost everything you could possibly need to know about operating & maintaining a greenhouse can be found right here.

      Very thorough & well thought out.

      Best Regards,

      Alternative Prime

    working

    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, hubpages.com uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at: https://hubpages.com/privacy-policy#gdpr

    Show Details
    Necessary
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the googleapis.com or gstatic.com domains, for performance and efficiency reasons. (Privacy Policy)
    Features
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Marketing
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Statistics
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)