Repsol YPF

There are many types of greenhouses. Some come in the form of a kit which can be installed by the home owner following the manufacturer’s instructions. Others are true pavilions which are complicated to put up and must be installed by a professional, and others involve using a glazed terrace. 
Irrespective of the structure and the size, the most important thing is for the area to have a series of fundamental elements to protect the plants correctly. These elements are: a source of heat/cold; different surfaces (tables, shelves and benches) on which to place the plant pots, seed trays, cuttings; a water supply; a source of light; curtains to protect the glazed walls; and a thermometer that measures the temperature and humidity.  
Another important aspect is the soil in the greenhouse, which should have a correct mixture of organic and mineral components. The ideal soil would be a combination of four different parts, one of peat, one of thick sand and two parts of the best garden soil. Pearl millet can be added to this composition (in the proportions specified by the manufacturer), to increase soil ventilation. 
 
Inside

The plants must be arranged in such a way as to  ensure their correct growth. It is essential to set up a large area (with a piece of chipboard or similar material) where you can place trays and boxes. The plants that need a lot of humidity should be placed on top of plastic trays containing moist river sand. The flowerpots should be placed on top of these trays. Plants that can tolerate a dry environment should simply be placed on top of the surface. It is important to arrange the plants according to their needs, in other words, those that need humidity are grouped together on top of trays containing moist river sand, such that they create a microclimate. The drier species are grouped together elsewhere in the greenhouse. 
The same approach must be taken where light is concerned. Plants requiring more light are placed in the brightest areas and those that need less light are placed in shady areas. Almost all plants can be damaged by the effect of direct sunlight. In order to protect them, the best thing to do would be to put up curtains or blinds on the glazed areas of the greenhouse that receive the most sun. 
If the greenhouse does not receive sufficient light for the plants to develop, they will die. In this case, you will need to find an appropriate source of artificial light, which gives off light but not heat. The best thing to do would be to discuss this with garden centre staff, since not all light bulbs are suitable for this purpose. Expert staff will inform the consumer of the most suitable type of light as well as the correct position in the greenhouse. 
Watering is another key issue. Ideally you will have a tap inside the greenhouse to which you can attach a hosepipe in order to be able to reach all of the plants. If you do not have one, you will have to use a watering can. 
 

Temperature and ventilation

The ideal temperature for plants is between 16ºC and 26ºC. In order to control it, you need a suitable thermometer that also measures the level of humidity. You must ensure that the inside of the greenhouse maintains the correct temperature (between the aforementioned minimum and maximum), using a heater where necessary, which will be switched on periodically, when there are sharp drops in the temperature.  
Double panels are also a good option for maintaining the heat during the winter. You can hang up plastic sheets inside the greenhouse which will act as additional panels. In summer or spring, the best thing to do is to use blinds or curtains, which will help to maintain a cool temperature inside the greenhouse. 
Ventilation is another essential parameter, since the air should never remain static. You can use a fan that keeps the air moving, or you can construct hatches in the walls and roof, which will be opened and closed depending on the plants’ needs. 

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