Today, many Russians who have homestead farms or summer cottages are thinking about building greenhouses. This solution allows you to diversify the diet – it’s nice to see fresh vegetables and herbs on your table throughout the year, as well as significantly support the family budget in our difficult times.
So, let us assume that your greenhouse is ready: the foundation has been built, the framework has been erected, there is glazing (polycarbonate or film), the soil has been buried, the beds have been created. Well thought out issues of watering and heating. It would seem that all taken into account. However, this is not quite true. Have you thought about lighting? And do you need it? After all, during the day, natural light is enough, and at night the plants need to rest. Why do plants need additional lighting and what should it be, what kind of lamps for heating a greenhouse exist today, we will try to tell in this article.
For normal development and intensive growth, plants need a large amount of energy. They get it from light rays: this is the sun in nature, and during greenhouse cultivation – special lamps.
What should be the light in the greenhouse?
Undoubtedly, solar lighting is most useful for agricultural crops, therefore it is necessary to use it as much as possible. However, the length of daylight hours (autumn, winter, and spring) does not allow one to grow crops fully – after all, plants need solar energy for at least ten to twelve hours a day. In any season (except summer), you will need to use lamps to illuminate greenhouses.
To create a comfortable environment for the growth of crops, you should follow simple rules.
- Artificial lighting of the greenhouse with LED lamps (as, incidentally, with any others) should not completely replace sunlight. It should serve only to extend the daylight. Therefore, the lamp for the greenhouse should be mounted in such a way that it does not limit the penetration of sunlight.
- In a greenhouse, light can be intense up to 16 hours per day (this depends on the crop being grown).
- Lighting plants should not be throughout the day: instead of growing crops, you get the opposite result – the weakening and depletion of sprouts.
- Plants need rest and darkness for 6 hours a day.
What kind of light do plants need?
All crops can be divided according to the principle of photoperiodicity. This means that each culture requires a special daylight duration for fruit formation. According to this principle, plants can be divided into:
- short day cultures — they need less than twelve hours (light) per day;
- a long day – the plants need more than twelve light hours.
How to choose a lamp?
Usually, crops grown to produce flowers and fruits require more light than those grown for leaves and stems. This must be taken into account when deciding which lamp for the greenhouse you need. Today, the trading network presents a huge selection of lighting fixtures for greenhouses. They differ in energy saving, the spectrum of the emitted light, cost and some other parameters.
What to look for when choosing a lamp?
First of all, you should ask the manufacturer of the lamp. Famous brands guarantee quality, after-sales service (which sometimes is expensive). Chinese lamps are attractive mainly because of their low price, but, unfortunately, you will get neither guarantees nor service.
Lamp power (W)
This indicator shows how much energy a lamp spends for a greenhouse per hour of work.
Knowing this parameter, you will be able to calculate how many lamps are needed for sufficient illumination of the greenhouse.
It should be recognized that to date a greenhouse lamp has not yet been created, which is capable of transmitting the spectrum of the sun’s rays 100%. Therefore, experienced owners often combine lamps to achieve the best result. Biological scientists were able to establish that a different light spectrum has a different effect on the crops grown.
For example, violet and blue rays accelerate photosynthesis – the plant becomes stronger and grows faster. Yellow and green rays slightly inhibit photosynthesis. In this case, the plant stems are stretched to a height and thinned. Orange and red rays are the best energy for fruiting and flowering plants, but you need to know that if they are oversupplied, the plant may even die. UV rays increase resistance to cold, they also form vitamins in fruits and leaves of plants.
Types of lamps for greenhouses
And now we will introduce you to the types of lamps, and you will determine what kind of lamp for the greenhouse you need. We hope that the information obtained will help you make the right choice.
This type of lighting is most often used in small greenhouses or greenhouses. They are universal and cost, and application – can be suitable for many. Ideal light quality can be achieved by combining warm white light with cold light.
Such a lamp for the greenhouse is able to work about 2000 hours. Often, for a complex effect on plants, an ultraviolet lamp is additionally installed, which prevents the development of harmful bacteria on the leaves of plants and in the soil. But it should be recognized that for large greenhouses it is better to choose a different type of lighting, since there will be too much luminescent lighting.
- In the first place – the efficiency of the device. Light emission of almost full spectrum. Therefore, they can be used at every stage of crop development, from growing seedlings to full maturity of the crop.
- Affordable price.
- High brightness.
- Such lamps do not heat up, therefore, do not violate the greenhouse microclimate.
- Do not require special technical skills for installation.
- The fluorescent lamp for the greenhouse is too large and may block the access of natural sunlight in the daytime.
- It has a low light output.
- It responds to changes in ambient temperature — a temperature of +25 degrees is required for its normal operation. When it is lowered, the lamp may simply go out.
- Does not maintain high humidity (no more than 70%).
Lamps are mounted above the plants in a horizontal position, fixed in a rectangular reinforcement of metal. They are located at a height of up to fifty centimeters for light-loving plants, and at a height of fifty centimeters and above – for plants that prefer not too bright lighting.
For growing plants in greenhouses and greenhouses produced mercury lamps – DRLF, contributing to the active photosynthesis of plants. Their emission spectrum is close to red, so they are best used during fruit ripening.
Nevertheless, you should know that the disadvantages of such devices more than advantages. These include:
- Danger in operation. Having broken such lamp, you will not be able to collect mercury balls. In this case, it is necessary to change the soil and destroy all plants.
- Such a lamp can not be thrown out after the end of its life. There is a special disposal method for this.
- Differs too intense ultraviolet radiation.
High pressure sodium lamps for greenhouses
They are classified as emitting red and orange parts of the spectrum. Experts suggest that the blue part of the spectrum of culture will receive from natural daylight.
- The main argument in favor of such lamps can be considered their efficiency. Such devices consume a small amount of electricity and at the same time are cheaper than analogues in terms of efficiency, for example, LED lamps. This is very important if you need to light a large greenhouse.
- In addition, sodium lamps for greenhouses work up to twenty thousand hours.
- Luminous efficiency is much higher than indicators of fluorescent lamps.
- Sodium lamps for greenhouses emit a lot of heat. This can be considered both an advantage and a disadvantage of the device. On the one hand, such lamps for the greenhouse in the winter are quite effective. They can be an additional source of heat. But in the spring, in the autumn, and, of course, in the summer such heating can damage the plants, and the owner will have to constantly monitor the temperature in the greenhouse.
- Such lamps adversely affect the development of young plants – the red part of their spectrum causes the seedlings to stretch, the stems become thin.
- Sodium lamps can attract harmful insects.
- Inside these fixtures is a mixture of mercury and sodium. Therefore (like mercury lamps) they are not safe in operation.
- Sodium lamps cannot be connected if voltage fluctuations in the network are more than 5%.
LED lamps for greenhouses
Most often they are called LED-lamps. Despite the fact that they are quite expensive, this type of lighting is becoming increasingly popular. By making a combination of such lamps, you can achieve light with the desired spectral composition – use individual lighting for any plant variety. Lighting greenhouses LED lamps allows you to adjust the intensity of light depending on the height of the devices and their number. For example, in the period of plant growth, you can give them more light with a blue spectrum, with fruit ripening – with red and orange.
- Energy Efficiency
- Work at very low voltage.
- Long service life (up to 100 thousand hours).
- Do not heat up – microclimate of the greenhouse is not broken.
- Eliminates the possibility of plants getting burns, even in the case of the closest distance to them.
- LEDs are resistant to moisture, temperature changes and mechanical damage.
- There is only one drawback to these lamps – the high cost.
Such a lamp for heating a greenhouse in winter is ideal. I must say that today more and more greenhouse owners prefer new infrared systems. These systems are efficient and economical, capable of creating indoor conditions in a greenhouse that are as close to natural as possible.
- Infrared lamps for the greenhouse well warm up the plants themselves and the soil.
- The air temperature rises from the energy given off by the walls of the greenhouse and the ground. This is the main difference between IR systems from electrical and convective methods, in which the air (heated) rushes up, while the plants and the soil remain cool.
- If desired, such heaters can be equipped with thermostats, which at a certain moment stop the heat supply and resume heating when the temperature decreases.
- Quickly warm the air. IR radiation does not pose a danger to humans or plants.
- Do not dry the air.
- The system is almost silent.
As you can see, today there are many fixtures for greenhouses. After reviewing their disadvantages and advantages, each owner will be able to choose a source of lighting suitable for his greenhouse.
Greenhouse Owner Reviews
According to people who grow vegetables in greenhouses, you can use different lighting. Both fluorescent and LED lamps are suitable for this. In the first case, the low cost of luminaires is attractive, in the second, the rapid growth of plants. However, most greenhouse owners prefer LEDs, despite their high cost. They fully justify their price by low power consumption and long service life.
Many refuse mercury lamps due to the fact that, having broken, such a lamp can cause many problems. If additional heating is needed, experienced growers recommend using infrared lights.