Want to build a greenhouse ?

NOTE: Want help building a greenhouse in Bangalore ? Get in touch with our landscaping team.

History

Greenhouse technology has come a long way since the time of the ancient Romans, but the concept – an enclosed structure providing a special environment for plants, is essentially the same today. The Roman gardeners used artificial methods, similar to the greenhouse system, of growing cucumber like vegetable throughout the year. They were planted in wheeled carts which were put in the sun daily and then taken inside to keep them warm at night.

In the 13^th century, greenhouses were built in Italy to house the exotic plants that explorers brought back from the tropics. In the 17^th century, the concept of greenhouses appeared in Netherlands and then England. Today, the Netherlands 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. In Japan, the first greenhouse was built in 1880 by Samuel Cocking, a British merchant who exported herbs. The geodesic dome was added to the many types of greenhouses in the 20^th century. Greenhouse structures adapted in the 1960s used wider sheets of polyethylene film which became widely available. This resulted in many more greenhouses being constructed on smaller farms and garden centres. 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. They are commonly covered with structured polycarbonate materials, or a double layer of polyethylene film with air blown between to provide increased heating efficiencies.

Location

A greenhouse should be located where it is protected from cold and wind. It should be positioned in such a way that allows maximum sunlight to reach to the plants for the maximum possible amount of time, particularly during winters. Keep it away from trees that might offer too much shade and drop leaves and branches on the structure. The site also needs good drainage, even if that means raising the floor so rainwater and irrigation water can drain off. The location of water, heat and electricity are further considerations.

Workspace

Your greenhouse interior should allow enough room for potting plants and moving about comfortably. Also take into consideration the height of the benches and tables you plan to use.  If you want a sink, where will you put it? Will you have storage space for tools? All of these questions should be dealt with before you begin to build your greenhouse.

Ventilation

Adequate ventilation is achieved when air can freely circulate among the plants. Spread your plants evenly throughout the greenhouse, rather than jamming them all onto one bench, so that the air is distributed evenly. Greenhouses overheat easily during summers if you don’t have a way to get rid of the excess heat. Choose your ventilation system by which region you live in and the size and design of your greenhouse.

The simplest option is to open up one or both doors in the morning depending on the weather report and leave them open until late afternoon. This will allow frost protection at night and some increased warming during the day.

Another alternative for cooling is the simple principle of water evaporation. Hose down your greenhouse floor and open your ceiling vents, and the entire unit will cool down quickly.

Heating

Greenhouses create a sheltered environment for plants by using solar radiation to trap heat. This helps to create an artificial environment in a greenhouse that can sustain plants when the outdoor temperature is too cool. Heat enters the greenhouse through its covering of glass or plastic and starts to warm the soil and plants inside. The warmed air near the soil begins to rise and is immediately replaced with cooler surrounding air that starts to heat up. This cycle raises the temperature inside the greenhouse creating a warmer microclimate inside.

In summers, the sun might do all the heating but when the temperature plummets, artificial heat may be necessary to maintain favourable temperature. This is done by natural or bottled gas, heating coils or heating fans. Solar energy can be captured during day time and released to boost the temperature during cooler periods. Waste heat 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. Heating or electricity is one of the most considerable costs in the operation of greenhouses especially in cold season.

Use

Greenhouses allow for greater control over the growing environment of plants.  They 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. Below are the main reasons for why amateur gardeners use greenhouse:

1. Raising plants for winter use.
2. Holding over garden plants to be used as “parent” plants next season.
3. Getting an early start for tender plants started from seed.
4. Increasing the possibilities of a greater variety and continuous supply.
5. Easier culture of small vegetables for winter use.
6. To propagate, and experiment with various plants as a hobby, or to develop new varieties.

NOTE: Want help building a greenhouse in Bangalore ? Get in touch with our landscaping team.

Reference Links:

1. http://en.wikipedia.org/wiki/Greenhouse
2. http://www.livestrong.com/article/124424-advantages-greenhouse/
3. http://davesgarden.com/guides/articles/view/3607/#b
4. http://www.envirocept.com/gh_guide/greenhouse_kits.html
5. http://www.organicgardening.com/learn-and-grow/tending-greenhouse