Simple DIY Backyard Greenhouse Plans & Ideas For Building a Small to Medium Size Greenhouse at Home…!

Building your knowledge concerning the different types of greenhouses will make the process so much easier. There are various different types including different sizes, shapes and building materials. Whether you are planning for a huge garden, a small garden, or an herb box, there are greenhouses available for you. Hobby gardening to commercial gardening can be accommodated.

Tips on growing tomatoes and gardening from Dave’s Garden.

The Greenhouse Effect maybe the most important natural phenomena and may lead to major changes in our lifestyles within our lifetime. Today, whenever there is a natural disaster, the Greenhouse Effect seems to be on the agenda. It wasn’t so long ago that scientists were dismissive of the Greenhouse Effect and there are some still that do not believe it exists, just like there are still people out there that think the world is still flat and the Holocaust never existed. So what is the Greenhouse Effect?

What is the Greenhouse Effect?
The Greenhouse Effect is the culmination of various Greenhouse gases that have been trapped in the Earth’s stratosphere that is leading to the changing of the word’s climate.

• Under the influence of the sun’s rays, the earth’s temperature varies from 0 to about 50oC with an average through night and day, winter and summer, of about 15o C

• The warming is done by rays from the sun, including the very shortest, ultraviolet (UV) rays and the longest infra-red (IR) rays which give you that warm feeling when you walk out into the sunshine, much like an electric radiator warms you when you turn it on and get close to it.

• Some of the incoming rays are reflected back by the clouds in the sky and others by the sea and land, particularly deserts and snowfields.

• Not all those reflected rays go back into space, instead, the atmosphere re-radiates many of the IR rays towards the earth making it warmer still. It is this ability of the atmosphere to re-radiate warm rays which creates the Greenhouse Effect.

• Water vapour, carbon dioxide and certain other trace gases, absorb some of this radiation and prevent it being sent back into space. This “blanket effect” keeps the earth warm. History of the Greenhouse Effect It is not a new phenomena or concept. The term “Greenhouse gas” was first used in the Nineteen Century, by Irish born scientist John Tyndall in a paper he wrote in London’s Philosophical Magazine in 1863. It wasn’t until the 1960’s that Professor Bert Bolin of Stockholm University worked on the phenomenon. When he discussed it with fellow scientists they said “This is science fiction. We don’t believe it”. However by the mid 1970’s things were starting to change rapidly as scientists were starting to accept he was right.

How do we know the Greenhouse Effect exists? What is the evidence?

1. Scientists have analysed climates on planets like Venus and our moon. Venus which is covered by a very dense atmosphere of carbon dioxide. Its surface temperature is around 500 deg C. Whilst the moon which has no atmosphere has an average temperature of approximately -18 deg C. Our atmosphere keeps the surface of our earth, with an average of 15 deg C, some 33 deg C warmer and thus habitable. Evidence of ice cores Over the past 160,000 years carbon dioxide and methane levels trapped in ice cores have varied with global temperature. Scientists have been able to drill out ice cores from the Arctic and Antarctic and measure the levels of carbon dioxide and methane.
Increase in surface temperature of approximately 0.5 deg C over 100 years as carbon dioxide levels increase Studies conducted by scientists have concluded that the earth’s temperature remained fairly constant until the start of the Industrial Revolution. Indeed it did not change much until the start of the twentieth century. From 1880 to 1940 there was a warming of just a quarter of a degree. Most of it was lost between 1940 and 1970. From 1950 to 1980 the average surface temperature was 15 deg C. Between 1970 and 1980 the temperature average went up by three-tenths of a degree C. 1987 and 1988 were the warmest years on record and since then temperatures have been increasing.  In 2009, Victoria Australia, experienced the hottest two days on record- 46 deg C, and one of the days (February 6th) leading to Australia’s worst natural disaster in which over 170 people died as a result of bushfires.

4. Sea levels are rising and small glaciers are melting.

Scientists using satellite and imaging technology have been able to monitor the melting of polar ice caps and glaciers.

What are the results of the Greenhouse Effect?

By using very sophisticated computer modeling, scientists have been able to predict what the world’s climate will be like when carbon dioxide levels have doubled.

Increase in world’s temperature It is thought that there will be an increase in the average global temperature by between 1.5 and 4.5 deg C . • By year 2030 an increase of 2 deg C, by 2100 an increase of 6 deg C. The warming will be greater at higher latitudes and in winter. This will lead to the melting of polar ice caps and glaciers which is already evident, in places like Greenland, the Arctic and Antarctic. Changes in World’s climate The Greenhouse Effect will lead to world-wide changes in weather and climate. Some places may get more rain and storms while other places may get less. Not all changes will be bad. However, almost everywhere in the world will have changes in weather, which will have a big impact on our lives Rising Sea Level It is estimated that by the year 2030, the average sea level will increase by approximately 20 centimetres. This will be due mainly to the melting of the polar ice cap, but also warming of the atmosphere will heat the upper layers of the oceans, which will expand when heated. For low lying countries in the Pacific like Tuvalu and Kiribati, and in the Indian Ocean like Maldives and other countries like Holland may altogether disappear. Other impacts Other impacts could be the dieing out of some species of animals and plants, such as coastal marine environments and coral reefs. Some plants would not be able to survive temperature increases. It takes thousands of years for forests to move north or south to cooler climates. According to Joel B. Smith, co-author of an EPA report states that “such a warming over a century would require forests to move five times faster than the fastest rate recorded by paleontologists since the end of the last ice age”.

What are the primary Greenhouse gases?

They are a number of organic compounds which have more than two bonds (i.e 3 atoms). The seven major Greenhouse gases are:

Carbon Dioxide (CO2) Ozone (O3) Methane (CH4) CFC’s (Freons F11 & F12) Water vapour (H2O) Nitrous Oxides (NOx) Ethane (CH3CH3)

Where do they come from?

Most of the Greenhouse gases have resulted from the burning of fossil fuels. Everything from power stations, motor vehicles, refrigerators, and factory emissions However, CO2 also results from deforestation which releases carbon locked in the soil when trees are felled. CH4 is released from agriculture such as sheep, cattle and manures and places such as tips, sewage treatment plants and mines.

Fossil Fuel contributions

Due to the nature of carbon to hydrogen ratio, different fossil fuels emit different levels of CO2.

Fossil Fuel Carbon to Hydrogen Ratio

Coal Approx.               1:1
Oil Approx.                  1:2
Natural Gas Approx.     1:4

• Hence combustion of coal produces twice the CO2 of natural gas

CO2 Levels in the atmosphere (parts per million)

Pre Industrial Revolution      270 ppm
1988                                  345 ppm
Today                               >355 ppm

By measuring bubbles of gases trapped in polar ice, scientists have shown that the amount of CO2 in the atmosphere prior to the Industrial Revolution was about 270 parts per million (ppm). A special monitoring station established atop from the mountain Mauna Loa in the Hawaiian Islands showed that by 1957 CO2 levels in the atmosphere to 315 ppm, an increase of 17%. By 1988, it had passed 345 ppm. A rise in 31 years of another 11%. An increased total of about 30% since the start of the Industrial Revolution. Expert’s further forecast that CO2 will reach a level of 500-700 ppm by the year 2050, a doubling inside 200 years.

Percentage Contribution of Greenhouse gases to the Greenhouse Effect

CO2                            55%
CFC (F-11/F-12)*         17%
CH4                            15%
NO                              26%
Other                            7%

* Please note that CFCs have been phased out since the mid-nineties

To stablise atmospheric concentration of various gases at present day levels, the following reductions would be required instantly:

CO2                     60%
CH4                    15-20%
NO2                    70-80%
CFC (F-11)*           70-75%
CFC (F-12)*           75-85%

Remaining Scientific Uncertainty
No argument that increasing concentrations of heat trapping gases will lead to an increase in average temperatures world-wide.

However there is an argument about the extent in some cases of various positive and negative effects.

1. Uncertainty in effects of clouds Cumulus- negative cooling effect reflect incoming sunlight High Altitude clouds- positive effect by trapping infra-red radiation from earth

This uncertainty explains variation in temperatures from 1.5 deg C to 4.5 deg C.

2. Combustion of fossil fuels e.g. coal to sulphur dioxide (SO2) has cooling effect.

3. Variations in sun’s output are responsible for temperature increases.

4. Ocean levels will naturally increase due to thermal expansion of surface ocean water and melting of glaciers.

An increase in temperature will lead to increased precipitation, which will increase ice thickness at poles, thus reducing sea level.

5. Natural regional climatic changes, such as deforestation and bushfires, as opposed to global changes.

Policies for Greenhouse Emission Reduction Problems

Different countries emit vastly different CO2 levels per capita Countries have very different per capita incomes Very difficult to work out the warming potential for each Greenhouse Gas in terms of CO2 equivalent. Emissions of gases from various countries are not known with certainty

Policies

1. Each country can reduce by the same percentage

Existing emission levels are uneven per capita are taken as standard Poor countries want to increase fossil fuel usage

2. Each country gets the same emission quotas on a per capita basis.These countries sell quotas to rich countries.

3. Rich countries could reduce emissions by 20% with no reductions required by poor countries.

• Not all rich countries have high emissions of CO2, and not all poor countries are low emitters because of deforestation.

4. Assume Australia which is high income and high Greenhouse Gas emitter per capita is required to reduce emissions by 20%.

• How should it be reduced? By: a) each state? b) each industry section?

Some methods of reducing CO2 emissions that have negative impact on our lives;
• Better managing of natural resource;
• Reducing waste in manufacturing;
• Find alternative end uses for waste (recycle and reuse);
• Buying less junks and goods that we don’t need (In Australia, estimated to be worth AUD$10 billion per annum);
• Buying quality goods that don’t need replacing as often;
• Recycling more (e.g. it takes about 8 times more energy to convert bauxite to aluminium than it does to recycle it)
• Reduced use of motor vehicles;
• Increased use of public transport;
• More efficient lighting, heating and cooling;
• Better insulation;
• Less reliance on electricity and electrical goods and machines;
• More efficient electrical appliances;
• More efficient cars;
• Alternative technologies from natural sources such as wind, thermal and tidal;
• Converting landfills and sewage plants into methane plants;
• Bio-fuels such as bio-diesel, methanol and ethanol production from organic waste sources
• Reduce large scale deforestation and land clearing;
• Increase tree planting;
• More efficient agriculture including No till and Conservation agriculture methods;
• Organic farming.

The successful management of a hobby greenhouse depends upon following simple rules regularly and applying common sense. A greenhouse is a responsibility rather like a dog or cat, for no day goes by without its inhabitants demanding some attention.

Regular watering may seem obvious, but it is surprising how many gardeners water when they have to, to the detriment of the plants. Good stable growth can never be achieved by irregular watering.

A humid atmosphere is beneficial, especially during the summer months. Regular spraying of the path and gravel under the benches helps. Avoid getting water on the foliage of plants during hot sunny weather. The droplets of water serve as small magnifying glasses during bright sunshine and the leaf tissue beneath becomes scorched.

During the late spring and peak summer period the greenhouse must be provided with some kind of shading. Roller blinds are expensive, but very effective, although most of the sun shade products that are mixed with water and applied with a brush are equally functional, if not as visually pleasing.

Ventilation should be applied freely during warm weather and moderately during cooler periods. The free circulation of air amongst plants helps to reduce the incidence of common fungal diseases like botrytis.

During the duller days of winter and early spring ensure that maximum light is admitted to the greenhouse. Clean the glass in the fall and then again during early spring. Cleanliness is important in all parts of the structure if pests and diseases are to be successfully controlled. The thorough cleaning of the rafters, brickwork and other fixtures during the winter with a strong garden disinfectant will pay dividends.

Dead leaves and discarded plants should be disposed of regularly and should not be allowed to accumulate beneath the staging where they will harbor pests and diseases. Regular cleaning and maintenance results in healthy plants and a trouble-free structure in which to produce them.

One of the on-going activities in a well managed greenhouse is re-potting. This applies to all permanent plants and those that are growing on and need periodic removal to a larger pot size. Some flowering plants like pot chrysanthemums and primulas are completely exhausted after flowering and are best discarded rather than re-potted. They rarely regain their former glory.

Re-potting often causes some consternation, particularly to new gardeners, for there is believed to be a certain mystique surrounding the operation and an uncertainty as to when to perform it. It is obviously better to re-pot a plant just before it needs it, but the beginner may have difficulty in recognizing just when that is, so plants are often allowed to go beyond that point and start to deteriorate.

Paleness of foliage and gaunt appearance is the overall aspect of a plant that is in need of re-potting. The pot-ball will be hard and congested, often with roots pushing out through the drainage holes of the pot. The compost surface will also probably have a stale look about it heightened by the presence of mosses or liverworts.

When re-potted, pot-bound plants rapidly recover from their ordeal, but it is better to catch them before they go into decline so that strong healthy growth can continue unchecked. During the active growing period do not be frightened to turn a plant out of its pot and inspect the root-ball. There is no need to pull it about, but a regular inspection will indicate whether everything is in good order.

Do not pay too much regard to the concentrated presence of roots towards the sides of the pot, for it is quite natural for them to gravitate there. It is not necessarily an indication that the plant must be re-potted. Similarly roots that push through the drainage holes may not always indicate congestion within the pot, for if the pot has been stood on a gravel tray in moist conditions it is quite normal for roots to probe around outside.

The best way to tell whether a plant needs re-potting is to pinch the root-ball with your fingers. If there is any flexibility in the compost it shows that the pot-ball has not been completely ramified by roots and therefore nothing need yet be done. If the root-ball feels hard and solid, then re-potting is clearly a matter of priority. Re-potting is also necessary if you spot tiny flies jumping around on the surface of the compost. These are feeding on decomposing organic matter in a compost that has passed its useful life. They disappear immediately after re-potting.

Most greenhouse plants need feeding if they are to give of their best. This is most effective when they are in active growth, either immediately after they have started to sprout or following the formation of flower buds. The feeding program is different for individual plant types, but the exact rates that should be used will be found on the containers of modern proprietary plant foods. The levels of nitrate, phosphate and potash are also noted, so that a suitable feed can be chosen depending upon whether it is to be directed to fruit and flower production or foliage and root development.

It is important to introduce a general spraying program to the greenhouse. Irrespective of the plants being grown, insect pests and fungal diseases will appear. Check carefully that the fungicide and insecticide mix so that you can spray in one go. Instructions will be clearly stated on the package. These will also indicate any plant sensitivity to the product.

Systemic pesticides are the only ones that can be used for such a spraying program. These are absorbed by the foliage, taken into the sap stream of the plant and serve as an inoculation. To maintain the protection, spraying will be required every three weeks or so. There are certain pests and diseases that are not controlled effectively by systemic products and these need dealing with individually with contact pesticides.