Backlighting of seedlings with fluorescent lamps

Traditional incandescent bulbs use many growers to illuminate seedlings, but they have no benefit. The emitted yellow-orange glow does not help the plants to grow. All useful range receive from light-emitting diodes or fitolamp. The disadvantage is the high cost of lighting equipment. A full replacement can be fluorescent lamps for seedlings, emitting the entire required light spectrum.

Light source device

In everyday life, fluorescent lamps are known as fluorescent lamps. The name comes from the white glow. The device consists of a housing with a diffuser. The lamp is a glass tube, sealed at both ends and working from the choke. The inner surface of the glass walls is covered with a white coating - phosphor. At both ends of the tube is fixed base. Through its contacts voltage is applied to the filament. The internal space under pressure is filled with argon and a small amount of mercury.

Attention! Breaking fluorescent lamps is dangerous.

In fluorescent and traditional incandescent bulbs there is one similarity - a tungsten filament. With the voltage applied, the spiral radiates heat, which contributes to the formation of UV radiation in argon and mercury vapor. For the human eye, the rays are not visible, and the plants benefit. In the deposition of phosphor there are phosphoric substances that form the spectrum and enhance the glow. Thanks to the additional components, the fluorescent tube glows 5 times stronger than a traditional incandescent lamp.

Seedling reaction to the backlight

Under natural conditions, plants develop under sunlight. Seedlings are grown on a window sill or greenhouse. Penetrating through glass daylight is not enough. It should be noted that the cultivation of seedlings falls on a period of short light days, and without artificial illumination is necessary.

Traditional incandescent lamps emit yellow-orange light that is useless to plants. The lack of UV rays inhibits the growth of seedlings and the process of photosynthesis. As a result, inadvertent shoots are observed, withering shoots on long thin legs. In the fall, this crop will produce a bad harvest, and during the growing season, the crops will be sore.

When the seedlings are illuminated with fluorescent lamps, conditions are created as close as possible to nature. In the UV rays there are two important colors: blue and red. The spectrum useful for the plant suppresses the harmful ranges of other flowers and contributes to the full development of the plants.

Useful and useless spectra

The full range of colors is present in sunny color, and it has the most positive effect on the vital activity of plants. Fluorescent tubes are able to provide seedlings with blue and red light. These colors are maximally absorbed by plants and benefit:

  • Blue color contributes to the proper development of cells. The stem of the plant does not stretch, but thickens and grows stronger.
  • Red color is useful for germinating seeds, and also accelerates the formation of inflorescences.
Important! Other colors, such as yellow and green, are reflected by the leaves. However, they are present in the sunlight, which means they are beneficial to plants.

Red and blue color are optimal for seedlings, but the percentage of benefit depends on absorption. There is such a thing as absent-mindedness. Direct rays absorbs foliage worse. If you use a matte reflector with a fluorescent lamp, the light becomes diffused. Rays of red and green become more favorable for the absorption of vegetation.

Varieties of light sources

Considering which fluorescent lamp is best for seedlings, it is worth considering that the light sources of this group are divided into two types.

Traditional daylight sources

The simplest cheapest option are fluorescent lamps for seedlings of economy class, used for room lighting. They emit daylight with a limited amount of blue and red. Different products form. The traditional "housekeeper" in the form of a spiral or U-shaped tubes, twisted into a chandelier holder, is similarly from this group. However, for the cultivation of planting material, this option is not suitable because of the small area of ​​illumination.

The best option is the tube. Lamps are produced in different lengths, which allows them to be distributed over the entire rack. The disadvantage of the light source is low power. You have to hang fluorescent lamps for seedlings of tomato or other garden crops as close as possible to the plants. According to the area of ​​coverage, the tube can replace 2-3 "housekeepers".

Tip! If you do not know how to choose fluorescent lamps for seedlings, read the characteristic on the package. A product with a cold or warm white glow is ideal for plants.

Phytoluminescent light sources

If you decide to seriously engage in the cultivation of seedlings, it is preferable to acquire phytoluminescent light sources. Lamps are designed specifically for lighting plants in greenhouses. Feature of the product is an unusual spectrum of emission, as close as possible to the characteristics of the sun. The composition is dominated by pink and lilac color. For human vision, radiation creates discomfort, and plants benefit.

The advantage of fitolamps is low power consumption, long service life and safe use. Due to its small size, the phytoluminescent lamp can be placed in a confined space, and it illuminates a large area.

The main disadvantage is the spectrum that is uncomfortable for the eyes. When growing seedlings inside the living room will have to take care of reflectors and protective partitions. The design should direct the glow to planting material as much as possible, and not to the eyes of residents.

Important! Glow phytoluminescent lamp can cause headaches.

Among the popular manufacturers of phytoluminescent lamps distinguished brands "Osram", "Enrich" and "Paulmann". Lighting devices are available in various capacities and almost all are equipped with reflectors.

Organization of the backlight

In order to correctly determine which fluorescent lamps are suitable for seedlings, one must know which optimal lighting is acceptable for the grown crops.


Each culture is sensitive to light. Some people like bright lights, while others like soft light. It is unprofitable to buy a lot of lamps, different power, to highlight different seedlings. Brightness is better to adjust the height of the hanging fixtures.

Cucumbers or cabbage love to hit direct sunlight. Lighting devices are separated from the tops of the seedlings at a distance of 20 cm. Eggplants, tomatoes and peppers experience discomfort under bright lighting. Fluorescent lamps are removed from the tops of the seedlings at a distance of up to 50 cm.

The height of the lamps is constantly monitored. Seedlings grow rapidly and its tips should not come close to the critical distance to the lamps.

Tip! To adjust the brightness, the backlight is connected via a dimmer. The device allows you to create an imitation of natural daylight, and also eliminates the frequent adjustment of the height of the hanging lamps above the plants.

Backlight duration

At different ages, planting material requires a certain backlight duration. In winter, in cloudy weather, fluorescent lighting is turned on for 18 hours. On sunny days, the backlight is turned off. Plants need to get used to natural light. Duration of artificial illumination is reduced to 12 hours.

The duration of the illumination depends on the age of the plants. After sowing the seeds above the boxes, they turn on the light around the clock to speed up the seedlings. Sprouted plants need rest at night. Constant lighting will not benefit. A good result gives the use of lamps with different characteristics. Combining lighting devices allows you to get a spectrum as close as possible to the sun's rays.

The video tells about the influence of light on seedlings:

Self-manufacturing backlight

In the manufacture of lighting, it is desirable to choose shelves of shelves and fluorescent tubes of the same length. The optimal size is 1 m. It is better to use factory-made lamps. The devices are compact, equipped with a switch, all the electrical elements are hidden under the casing, and the glass tube is covered with a plastic matte diffuser.

In a homemade backlight, the cover of the socket base with the cartridge must be hidden by the casing. The wiring is laid along the rails of the rack. The choke is installed in the box further from the lamps so that when watering the seedlings the water does not cause a short circuit.

Attach the light from the bottom side of the shelf of the upper tier of the rack. The glass surface of the tube should not be in contact with any objects. On wide shelves it is optimal to install 2 lamps on the edges. If the brightness of the backlight will be regulated by a dimmer, the devices can be fixed to the shelves with rigid steel ribbons. Otherwise, the lamps are hung on a rope to adjust the height.

When organizing seedling lighting, you need to remember about electrical safety. Water entering the lighting device during watering will create a short circuit. There is even a threat of destruction of the glass tube, where mercury is dangerous to humans inside.