Additional artificial lighting of flowers and plants in the apartment

Every experienced gardener knows the huge role that properly selected lighting for indoor plants plays. Along with watering and soil, light is an indispensable component on which successful growth directly depends. It is no secret that in the natural environment, some plants thrive in shaded areas, while others cannot develop without direct exposure to sunlight. At home, the situation looks similar. Let's talk in detail about how to properly make artificial lighting for indoor plants.

Phytolamps

The summer season begins at the beginning of spring. Gradually, the soil and air warm up, and gardeners prepare the seedlings for planting in natural sunlight. However, many lovers of fresh greens, which they eat all year round, and city farmers know that it is not necessary to wait until spring and summer to plant plants.

• Why do you need additional lighting for seedlings?
• What is a phytolamp
• Pros of phytolamps
• Types and forms of phytolamps Sodium gas-discharge lamps (DNAT)
• Metal halide (MGL)
• Mercury gas-discharge phytolamp (DRLF)
• Fluorescent lamps
• LED phytolamps

TOP 5 powerful phytolamps according to plant growers

Lamp DNAZ Reflux 600 W SUPER is a powerful sodium lamp with a reflector in a dust- and moisture-proof version with an E40 socket. The area illuminated by 1 lamp reaches 6.5 m. Light intensity is 86,000 lm, color temperature is 2100K.

HPS lamp Green Power 600 W is a powerful classic sodium phytolamp with bright orange light, suitable for vegetation and flowering, with a standard E40 socket. The light intensity is 87550 lm, but an additional reflector is needed. Light stability is maintained for 20,000 hours.

HPS lamp Prima Klima Sunkraft 400 W is a sodium lamp without a reflector with reduced heat generation, suitable for the vegetative growth stage and the flowering and fruiting period of crops. Depending on the type of plants grown, together with a reflector it can illuminate from 0.8-1 m2 of area. Light intensity 53500 lm, service life 32000 hours.

GroLux 600 W HPS lamp is a powerful lamp for amateur and professional use, suitable for all stages of agricultural life. Light intensity 90,000 lm, color temperature 2050K, standard cartridge E40. It gets very hot, so a closed lamp with a reflector and hot air outlets is recommended.

ESL lamp Foton 250 W 6400K E40 is a fluorescent lamp with a standard E40 socket that does not require a ballast. But you need a reflector to increase the efficiency of the flow, the intensity of which is 13800 lm. The lamp does not get very hot, can be located close to plants, and is well suited for the vegetative phase of greenery, low crops, rooting cuttings, forcing seedlings.

Why do you need additional lighting for seedlings?

Thanks to artificial light sources, it is possible to grow seedlings in the complete absence or insufficient lighting. Electric lighting devices have a different set of spectra aimed at activating physiological processes in plants.

With their help, photosynthesis reactions are launched and new compounds are formed. Thanks to them, seeds quickly germinate into sprouts and adult plants, which after a short period of time produce excellent harvests.

Signs of lack of light

There are a number of signs by which it is easy to identify a lack of light. You just need to take a close look at your flower and compare it with the standard. For example, find a similar view on the Internet. A clear lack of illumination manifests itself as follows. The plant slows down its growth. The new leaves are smaller and the stem becomes thinner. The lower leaves turn yellow. The flower either stops blooming completely, or the number of buds formed is less than the statistical average. It is assumed that watering, humidity and air temperature are normal.

What is a phytolamp

A phytolamp is an electrical source of electromagnetic radiation, specially designed for growing plants. The spectra of phytolamps are already built into the modular design of a specific model or can be independently adjusted for different crops and growth stages.

Through phytolights, the processes of photosynthesis that occur in plant chloroplasts are activated.

The growth and development of greenery depends on their speed. Therefore, you need to approach the choice of phytolamp thoroughly. Growing plants requires a special spectrum, light output and color temperature of the light source.

Phytolamps or agrolamps are much more economical than conventional light bulbs, taking into account the luminous flux output . They are intended for plants. As they are used, active growth of seedlings is observed, susceptibility to the environment and stress is reduced, flowering is stimulated and productivity increases

Types of lamps for supplementary illumination of seedlings

The abundance of such light sources is divided into the following options:

• sodium;
• halogen;
• luminescent;
• LED

In theory, seedlings can be illuminated with ordinary incandescent light bulbs. But the profitability of this option will be low. Conventional lamps consume more energy, do not last long, and heat up excessively. And their light spectrum is not the most ideal. Therefore, it is better to use specialized equipment.

Halogen lamps are also not the most suitable option. They are durable and produce light with suitable characteristics. However, even small voltage drops can damage them. They also require up to 20 minutes to fully turn on. And the brightness of their glow begins to fall after 2 thousand hours of operation.

HID lamps are a much more efficient option. Here are their advantages:

• high efficiency;
• working life up to 20 thousand hours;
• optimal color spectrum.

The main disadvantages are the need to connect through a special starting unit and the overall high cost of sodium supplementary lighting systems.

LED systems and fluorescent lamps are more accessible, practical and have optimal characteristics. The first option is characterized by a long service life (over 50 thousand hours), virtually no heating and high reliability. The diodes have no filaments or spirals, so they are not afraid of shaking. And the light they generate is safe for humans and optimally suited for plant development.

Fluorescent lighting also fully meets the physiological needs of plants. In addition, such lamps create a wide and uniform luminous flux, are durable and reliable. The disadvantages of this type include higher cost and the content of mercury vapor in the flask.

Thus, for home use it is worth buying a fluorescent or, more practical, LED phytolamp. Based on the combination of performance characteristics, reliability and price, this will be the best option. Moreover, as statistics show, diode lamps have firmly taken the leading place.

Pros of phytolamps

• Lighting is aimed at the crops, and not throughout the room;
• You can use phytolights in rooms with normal lighting;
• Plants grow faster, bloom and bear fruit, remaining healthy and strong;
• Phytolamps allow you to grow various crops all year round;
• Agropanels consume little electricity compared to incandescent lamps;
• Innovative phytolamps are equipped with technology for removing excess heat.

The disadvantages include the fact that the light of some types of phytolamps is harmful to humans and therefore it must be installed in a non-residential area. Additionally, fixtures take up space and must be mounted correctly to achieve the desired effect.

Main signs of insufficient lighting

With insufficient sunlight, the plant quickly begins to change its appearance. The leaves become less saturated in color, and sometimes simply begin to crumble. In some cases, it is possible that round spots may appear on the surface of the leaf plate.

The flower noticeably increases in height. The stem becomes thin and lifeless.

If one of these symptoms is detected, it is necessary to change its location on the window opening.

To quickly restore the plant, you can install an additional light source. How to decorate lighting for indoor plants? Everything is quite simple.

For this you will need:

• LED Strip Light;
• table or standing lamp designed for indoor plants.

To normalize the life processes of plants, there are special types of lamp lighting.

For each type, it is necessary to select the appropriate intensity of artificial radiation. The photo of indoor flower lighting shows a variety of designs.

Tropical species require more powerful devices. As for indoor violets and orchids, a small flow of lighting is enough for them. Such devices have several modes for simulating solar radiation.

Types and forms of phytolamps

According to the complexity of use, spectra and emitted light, phytolights are divided into the following lamps:

Sodium gas discharge lamps (HSD)

They are used in greenhouses for growing seedlings and garden crops, most often to extend daylight hours (additional light). Such phytolamps are not suitable for growing plants at home. They are too powerful and heat up quickly.

Such phytolamps are divided into basic ones, when the light is distributed throughout the entire room and with a mirror coating. In this case, lighting has a directed effect on the crops themselves. The lamps emit yellow-green and orange light, but the spectrum differs significantly from the natural one and is poorly transmitted. They need special lamps. They work for a long time under any climatic conditions, but quickly lose their luminosity; in addition, problems arise with their disposal, since they contain mercury vapor.

Metal halide (MGL)

They are a type of gas discharge lamps. There are halogen vapors in the MGL flask. Phytolamps of this type require durable lamps. Metal halide lamps can operate continuously for up to two years, but require a stable voltage, are explosive and also quickly lose their luminosity.

They are more expensive due to the fact that they have high light output and different lighting spectra for different crops.

Mercury gas-discharge phytolamp (DRLF)

Suitable for any lamp. Thanks to mirror coating, the lamp directs light to a specific location. DRLFs are durable in use, provide bright light, but distort colors. In addition, such lamps require constant voltage without interruption.

Fluorescent lamps

- This is a type of gas-discharge phytolamps, but for growing plants, those that have the desired luminescence spectrum are selected. Usually used in everyday life, they are economical, cheap and safe. However, they cannot work in rooms with temperatures below +5°C. In addition, fluorescent lamps have a low degree of luminescence and are not suitable for commercial and industrial use.

LED phytolamps

can be assembled into different lighting systems, they are available and have different emission spectra. They are not demanding on voltage and can operate at full power immediately after switching on. LEDs consume little electricity, are very durable, they can be used to select any spectrum of light for various crops and tasks, and they lose efficiency very slowly. However, they should not be allowed to overheat significantly.

How to calculate the number of lamps and light level

The lighting and the number of light bulbs selected depends on the lighting needs of green spaces. Lighting is calculated as a proportion of power to the area of ​​the flower.

Per 100 sq. dm. necessary:

• 2.5 W - for light-loving people;
• 1.5-2.5 W - for those who prefer moderate light;
• 0.5-1.5 W - for shade lovers.

In terms of the degree of luminous flux, 1 Watt of power of a fluorescent light bulb creates 70 Lm, an incandescent lamp - four times less. Taking this value into account, the number and power of devices is calculated. For example, for a window sill with an area of ​​100 sq.dm, the following power is required: 2.5 W x 100 sq.dm = 250 W. For such an area you need 2-3 light bulbs of 70 W each.

However, this calculation is approximate, which can be used as a guide when choosing devices. It is better to use oblong and powerful lamps: they have high light output, and it is better to purchase two devices of 34 W each than four of 17 W each.

Plants are divided into three groups according to their sensitivity to light:

• shoots that love secluded darkened corners;
• flowers that are comfortable both in the shade and in the sun;
• greens that prefer to grow in open sunny spaces.

Photophilous

Illumination requirements - 4000-6000 lux - a unit of measurement of lighting power. This group includes: azalea, Kalanchoe, amaryllis, abutilon. Shade-tolerant flowers with variegated colors need the same lighting as light-loving ones, since they naturally grow in open, sunny places.

Shade-tolerant

Requirement: 1000-3000 lux. This species includes: ivy, anthurium, dieffenbachia, philodendron and many others. They do not require additional lighting if they are located on the windowsill, but in the depths of the room during the winter season they need lighting.

Shade-loving

Requirement: 500-800 lux. Unpretentious plants that require diffused lighting for normal development. But if it is deficient, they may lose their attractive appearance. This species includes: arrowroot, calathea, stromanta. Such species need soft and diffused light, otherwise they will suffer.

How to choose a phytolamp for plants

There are many types of lamps and each has its own advantages and disadvantages. What should you pay attention to when choosing a phytolamp for plants? To choose the appropriate option, you need to decide on the purpose of purchase and the place where the phytolamp will be installed in the future.

If you need a phytolamp for growing plants on a windowsill, then there are many types to suit every taste and budget. A more difficult task is to find a phytolamp for seedlings and plants grown in greenhouses or specialized premises at the production level. It is worth considering how long the phytolamp will work, continuously or seasonally, and how often it requires maintenance and replacement during operation. Before buying a phytolamp, it is worth checking how demanding it is in terms of voltage, what spectrum of radiation it produces, what power it has, what material it is made from, the illumination area and the luminous flux power (PPFD) at different heights from the surface of the lamp to the plant.

It is also necessary to correctly calculate, based on the area of ​​the room and the crops that the city farmer is going to grow, the required number of phytolamps, their power and spectrum. Many of them emit a lot of heat, so it’s worth choosing models that are equipped with cooling radiators and technologies for removing excess heat.

For the growth and development of various plants, they need blue, red light at different wavelengths, infrared radiation, and sometimes ultraviolet. Therefore, you need to understand this before purchasing phytolamps. An important factor is the ease of assembly and dismantling of the lamps.

Phytolamps come in round, square and linear shapes. The choice should be made on the lamp that, in terms of power and area, will optimally illuminate the plants. Round, square or spotlights are suitable for illuminating a free-standing plant.

The advantages of such phytolamps are high power, compactness, the ability to combine spectra and ease of use. 36 W agricultural lights illuminate plants that are grown at home. Phytolamps with a power of 100 W or more are used in greenhouses. To grow plants in long containers in one row, linear phytolamps are used. However, for a safe but effective glow, it is necessary to calculate the optimal height for installing the lamps. It is also worth considering the area of ​​radiators and illumination.

How much light do you need?

It is impossible to give a definite answer to this question. Just as a person can live in different parts of the globe, so an indoor flower can grow on a windowsill facing north, south, west or east. Throughout its life, the plant will strive to adapt to current conditions: stretch upward due to lack of light or, conversely, expose the next blossoming bud to the sun’s rays.

By observing the appearance of the stems and leaves, the size and number of flowers, you can determine the adequacy of the lighting level. At the same time, do not forget about what stage of development the indoor flower is at: growing season, flowering, seed ripening. At each stage, it takes light from the sun of the wavelength that it needs at the moment. Therefore, when organizing additional lighting, it is important to take into account the qualitative component of the light flux.

Long-term exposure to bright light from the sun and lamps with an illumination level of more than 15 thousand lux is favored by those indoor flowers that grow in the open air in their natural habitat. These are many people's favorite crassula, geranium, kalanchoe, and begonia. Artificial lighting for plants of this type in the evening will benefit them.

Representatives of the flora that feel comfortable in illumination of 10–15 thousand lux include spathiphyllum, clivia, saintpaulia, tradescantia and dracaena. The leaves of these types of indoor flowers do not like hot sunlight, but also do not tolerate early twilight. Therefore, the ideal place for them would be a window sill with access to the west, where in the evening their leaves will receive the necessary energy from the setting sun.

So-called shade-loving plants can bloom and develop away from the window opening, being content with illumination of up to 10 thousand lux. However, this does not mean that they will die if they are placed in a brighter place. They just need less direct sunlight. These include some types of ficus and dracaena, philodendron, as well as tropical vines.

What are lenses for?

As the plants develop, the phytolamps are raised so as not to damage the crops. However, after such manipulations, most of the light is scattered without reaching the sprouts. In order to avoid this, additional mirror lenses are installed. In spotlights, the lenses are built in at an angle of 60°. In linear phytolamps, the lenses must be installed independently, or you must select lighting fixtures that come with lenses. And so that the angle of illumination changes by 15° with every 10 cm of crop height.

White light for plants

Photosynthesis and light

Sunlight is necessary for plants at any stage of development.
The main characteristics of light are its spectral composition, intensity, daily and seasonal dynamics. Lack of light - shortened daylight hours and low light intensity - lead to the death of the plant. Light is the only source of energy that provides the functions and needs of a green organism. To compensate for the lack of sunlight, additional lighting of plants is used. The most common tools are HPS lamps and LED lamps. Photosynthesis is the basis of plant life. The energy of light quanta converts inorganic substances produced by the plant into organic ones.

Light of different wavelengths has different effects on the rate of photosynthesis. The first studies on this topic were carried out back in 1836 by V. Daubeny. The physicist came to the conclusion that the intensity of photosynthesis is proportional to the brightness of light. The brightest rays at that time were considered yellow. Outstanding Russian botanist and plant physiologist K.A. Timiryazev in 1871–1875 found that green plants most intensively absorb rays from the red and blue parts of the solar spectrum, and not yellow ones, as was previously thought. By absorbing the red and blue parts of the spectrum, chlorophyll reflects green rays, which is why it appears green. Based on these data, the German plant physiologist T.V. Engelman in 1883 developed a bacterial method for studying the assimilation of carbon dioxide by plants, which confirmed that the decomposition of carbon dioxide (and, therefore, the release of oxygen) in green plants is observed in additional to the main color (i.e. green) rays - red and blue. Data obtained using modern equipment fully confirm the results obtained by Engelman more than 130 years ago.

Fig. 1 – Dependence of the intensity of photosynthesis of green plants on the light wavelength

The maximum intensity of photosynthesis is under red light, but the red spectrum alone is not enough for the harmonious development of the plant. Research shows that lettuce grown under red light has more green mass than lettuce grown under combined red-blue light, but its leaves have significantly less chlorophyll, polyphenols and antioxidants.

PAR and its derivatives

Photosynthetically active radiation (PAR, PPF - Photosynthetic Photon Flux) is that part of solar radiation reaching plants that is used by them for photosynthesis. Measured in µmol/J. PAR can be expressed in energy units (radiation intensity, Watt/m2).

Photosynthetic Photon Flux Density (PPFD) is the total number of photons emitted per second in the wavelength range from 400 to 700 nm (μmol/s).

The PAR value does not take into account the difference between different wavelengths in the range of 400 - 700 nm. In addition, the approximation is used that waves outside this range have zero photosynthetic activity.

If the exact emission spectrum is known, it is possible to estimate the photon flux assimilated by the plant (YPF - Yield Photon Flux), which is PAR weighted in accordance with the efficiency of photosynthesis at each wavelength. YPF is always slightly less than PPF, but allows a more adequate assessment of the energy efficiency of the light source.

For practical purposes, it is enough to take into account that the dependence is almost linear and PPF for 3000 K is approximately 10% greater than YPF, and for 5000 K - by 15%. Which means about 5% more energy value for a plant in warm light compared to cold light at equal lux.

White LED Efficiency

Isolated and purified in vitro chlorophyll only absorbs red and blue light. In a living cell, pigments absorb light in the entire range of 400–700 nm and transfer its energy to chlorophyll.

A few facts about white LEDs:

1. In the spectrum of all white LEDs, even with a low color temperature and maximum color rendering, like sodium lamps, there is very little far-red (Fig. 2).

Rice. 2. Spectrum of white LED (LED 4000K Ra = 90) and sodium light (HPS)

in comparison with spectral functions of plant sensitivity to blue (B),

red (Ar) and far-red light (Afr)

Under natural conditions, a plant shaded by a canopy of alien foliage receives more distant red than near red, which in light-loving plants triggers the “shade avoidance syndrome” - the plant stretches upward. Tomatoes, for example, at the growth stage (not seedlings!) need far red to stretch, increase growth and the total area occupied, and, therefore, the harvest in the future. Under white LEDs and HPS lamps, the plant feels like it is under the open sun and does not stretch upward.

2. Blue light provides phototropism - “following the sun” (Fig. 3).

Rice. 3. Phototropism - turning leaves and flowers, stretching stems

to the blue component of white light

In one watt of white LED light there is twice as much phytoactive blue component in 2700K as in one watt of sodium light. Moreover, the proportion of phytoactive blue in white light increases in proportion to the color temperature. If you place a lamp with intense cold light next to the plant, it will turn the inflorescences towards the lamp.

3. The energy value of light is determined by color temperature and color rendering and can be determined with an accuracy of 5% using the formula:

[eff.µmol/J], where η – light output [Lm/W],

Ra – color rendering index,

CCT – correlated color temperature [K]

This formula can be used to calculate illumination in order to provide the required YPF value for a given color rendering and color temperature, for example, 300 effective µmol/s/m2:

Table 1 – Illumination (lux), corresponding to 300 effective µmol/s/m2

The table shows that the lower the color temperature and the higher the color rendering index, the lower the required illumination. However, given that the light output of warm light LEDs is somewhat lower, it is clear that there is no energetically significant gain or loss by choosing color temperature and color rendering. You can only adjust the proportion of phytoactive blue or red light.

4. For practical purposes, you can use the rule: a luminous flux of 1000 lm corresponds to PPF = 15 μmol/s, and illumination of 1000 lux corresponds to PPFD = 15 μmol/s/m2.

PPFD can be calculated more accurately using the formula:

PPFD = [μmol/s/m2],

where k is the luminous flux utilization factor (the proportion of the luminous flux from the lighting installation falling on the leaves of plants)

F – luminous flux [klm],

S – illuminated area [m2]

But k is an uncertain quantity, which increases the inaccuracy of the estimate.

Let's consider possible values ​​for the main types of lighting systems:

Take advantage of our catalog of LED lighting for plants

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LED LIGHTING FOR PLANTS

You may also be interested in:

• minigarden lighting
• Lamps for seedlings
• LED lighting for greenhouses
• For plant photosynthesis
• Phyto LEDs

Point and line sources.

The illumination created by a point source in a local area falls in inverse proportion to the square of the distance between this area and the source. Illumination created by linear extended sources over narrow beds decreases inversely with distance. That is, the greater the distance from the lamp to the plant, the more light does not fall on the leaves. Therefore, it is not economically feasible to use lamps located at a height of more than 2 m to illuminate single extended beds. The use of lenses allows you to narrow the luminous flux of the lamp and direct a larger share of light to the plant. However, the strong dependence of illumination on distance and the uncertainty of the effect of using optics do not allow us to determine the utilization factor k in the general case.

· Reflective surfaces.

When using closed volumes with perfectly reflective walls, the entire light flux hits the plant. However, the actual reflectance of mirror or white surfaces is less than unity. The proportion of light flux incident on the plant depends on the reflective properties of surfaces and volume geometry. It is generally impossible to determine k.

Large arrays of sources over large landing areas

Large arrays of spotlights or linear luminaires over large planting areas are energetically beneficial. A quantum emitted in any direction will eventually hit some plant; the coefficient k is close to unity.

So, the uncertainty in the fraction of light reaching the plants is higher than the difference between PPFD and YPFD, and higher than the uncertainty determined by the unknown color temperature and color rendering. Therefore, for practical assessment of PAR intensity, it is advisable to choose a fairly rough method for assessing illumination that does not take these nuances into account. And if possible, measure the actual illumination with a lux meter.

The most adequate assessment of the photosynthetically active flux of white light is achieved by measuring the illumination E using a luxmeter and neglecting the influence of spectral parameters on the energy value of light for the plant. Thus, the PPFD of white LED light can be estimated using the formula:

PPFD = [μmol/s/m2]

Using the above formulas, let us evaluate the applicability of the DS-Office 60 LED office lamp for growing lettuce and its PPFD.

The lamp consumes 60W, has a color temperature of 5000K, color rendering Ra =75 and luminous efficiency of 110 lm/W. At the same time, its effectiveness will be

YPF = (110/100) (1.15 + (3575 − 2360)/5000) eff. µmol/J = 1.32 eff. µmol/J,

which when multiplied by the consumed 60 W will be 79.2 eff. µmol/s.

If the lamp is placed at a height of 30-50 cm above a bed with an area of ​​0.6 × 0.6 m = 0.36, the lighting density will be 79.2 eff. µmol/s / 0.36 m2 = 220 eff. µmol/s/m2, which is 30% lower than the recommended value of 300 eff. µmol/s/m2. This means that the lamp power needs to be increased by 30%.

PPFD = 15×0.110klm/W×60W/0.36m2=275 µmol/s/m2

Efficiency of phytolight DS-FitoA 75. (75W, 5000K, Ra = 95, 102 lm/W):

YPF = (102/100)(1.15 + (3595 − 2360)/5000) eff. µmol/J = 1.37 eff. µmol/J, or 102.75 eff. µmol/s. With a similar location above the bed, the lighting density will be 285 eff. µmol/s/m2, which is close in value to the recommended level.

PPFD = 15×0.102klm/W×75W/0.36m2=319 µmol/s/m2

Efficiency of DNAT

Agricultural complexes are conservative when it comes to lighting greenhouses and prefer to use time-tested sodium lamps. The efficiency of HPS depends on the power and reaches a maximum at 600 W. YPF is 1.5 eff. µmol/J. (Fig. 4). 1000 lm of luminous flux corresponds to PPF = ~12 µmol/s, and illumination of 1000 lux corresponds to PPFD = ~12 µmol/s/m2, which is 20% less than similar indicators of white LED light. These data make it possible to recalculate lux for HPS in µmol/s/m2 and use the experience of lighting plants in industrial greenhouses.

Rice. 4. Spectrum of a sodium lamp for plants (left). Efficiency (lm/W and eff.µmol/J) of commercial sodium lamps for greenhouses (right)

Any LED lamp with an efficiency of 1.5 eff. µmol/W is a worthy alternative to a HPS lamp.

Rice. 5. Comparative parameters of a typical 600W sodium lamp for greenhouses, a specialized LED phytolight and an office lamp.

An ordinary general lighting lamp for supplementary illumination of plants is not inferior in energy efficiency to a specialized sodium lamp or a red-blue lamp. The spectra show that the red-blue phytolight is not narrow-band, its red hump is wide and contains much more far-red red than the white LED and sodium lamps. In cases where far-red is required, using such a luminaire alone or in combination with other options may be advisable.

Currently, both red-blue and white light are used to illuminate hydroponic farms (Fig. 6-8).

Fig. 6 – Fujitsu greens farm

Rice. 7 – Toshiba hydroponic system

Fig. 8 – The largest vertical farm Aerofarms, supplying over 1000 tons of greens per year

There are very few published results of direct experiments comparing plants grown under white and red-blue LEDs.

The main direction of research today is to correct the shortcomings of narrow-band red-blue lighting by adding white light. Experiments by Japanese researchers show an increase in the weight and nutritional value of lettuce and tomatoes when white is added to red light.

Rice. 9. In each pair, the plant on the left is grown under white LEDs, on the right - under red-blue LEDs

(from a presentation by I. G. Tarakanov, Department of Plant Physiology, Moscow Timiryazev Agricultural Academy)

The Fitex project presented the results of an experiment on growing various crops in the same conditions, but under light of a different spectrum. The experiment showed that the spectrum affects the crop parameters. You can compare plants grown under white light, under HPS light and narrow-band pink light in Fig. 10:

Rice. 10 Lettuce grown under the same conditions, but under a different spectrum of light.

Images from a video published by the Fitex project in the materials of the Agrophotonics Technologies conference in March 2022.

In terms of numerical indicators, the first place was taken by a unique non-white spectrum under the commercial name Rose, which in shape is not very different from the tested warm white light with high color rendering Ra=90. It differs even less from the spectrum of warm white light with extra-high color rendering Ra=98. The main difference is that in Rose, a small portion of the energy from the central part is removed (redistributed to the edges) (Fig. 11):

Fig. 11 – Spectral distribution for warm white light extra high color rendering and Rose light

The redistribution of radiation energy from the center of the spectrum to the edges does not affect the life processes of plants, but the light becomes pink.

The influence of light quality on the result

The plant's response to light - the intensity of gas exchange, nutrient consumption and synthesis processes - is determined in the laboratory. The responses characterize not only photosynthesis, but also the processes of growth, flowering, and the synthesis of substances necessary for taste and aroma (Fig. 12).

Fig. 12 - The influence of certain colors of the solar spectrum

at various stages of plant development

Regular white LED light and specialized red-blue light have approximately the same energy efficiency when lighting plants. However, broadband white promotes the complex development of the plant, not limited to just stimulating photosynthesis. Removing green from the full spectrum to make purple from white is nothing more than a marketing ploy.

Red-blue, pink LED light or yellow HPS light can be used in industrial greenhouses. But if additional illumination of plants occurs in the constant presence of a person, white light is needed that does not irritate visual and nerve receptors.

The choice of the type of LED lamp or HPS lamp depends on the characteristics of growing a particular crop, but in any case it is necessary to take into account:

· Photosynthetic photon flux PPFD and assimilated photon flux YPF. Now you can calculate these indicators yourself, knowing the luminous flux of the lamp, color rendering index and color temperature.

Recommended value YPF=300 eff. µmol/s/m2

· The degree of protection of the lamp body from the penetration of dust and moisture. When IP is below 54, soil particles, pollen, and water drops may get inside when watering, which will lead to failure of the lamp.

· Presence of people in the room with working lamps. Pink and violet light is tiring for the eyes and can cause headaches, while yellow light distorts the colors of objects.

· HPS lamps heat up during operation; they must be suspended at a considerable height to avoid burns and drying out of the soil. The luminous flux of gas-discharge lamps decreases after 1.5-2 years of use.

Properly selected light ensures rapid and proper development of plants - strengthening the root system, increasing green mass, abundant flowering and accelerated ripening of fruits.
Technological progress is taking crop production to a new level - use its fruits! Phytolights

At what height should you hang a phytolamp?

The optimal height is the one at which maximum effect is achieved without negative impact. The closer the phytolamp is located to the plants, the more power of the light flux they receive and grow faster, but too close a distance can destroy the plant. Moreover, in order to prevent excessive glow, it is necessary to install reflectors or reflectors.

To obtain a positive effect, the phytolamp is installed taking into account the fact that every 1 m2 of area is illuminated with a power of 70 W or more with a lamp installation height of 25-50 cm from the plants. In addition, in winter it is necessary to increase the duration of daylight hours by 4-5 hours.

The larger the plant grows, the closer the phytolamp should be. Moreover, the height of the suspension should be calculated from the top of the plants, and not from the ground. In addition, it is worth considering that crops are divided into light-loving and shade-loving varieties.

How important is lighting for plants?

“When talking about lighting for plants, we must understand that we are not talking purely about the source of its supply, but about the spectral diversity of the light flow, to which, in fact, the flora reacts”

Light is a vital factor for green spaces, since almost half of their dry mass consists of carbon produced from air masses, and the process of its assimilation (photosynthesis) occurs only during the daytime. Naturally, its activity is influenced by many other factors, but still the intensity of illumination of plants is the main one.

Lack of sun exposure primarily affects young growth. Their leaf blades thin out very quickly. The shoots lose their color saturation and growth slows down. The stems of such plants extend along with the internodes in the direction of the light flow.

There are other symptoms of light deficiency that can appear even in house flowers living in a backlit plant niche. And you need to be able to recognize them.

Without lighting, plants experience light deficiency

The first of them is the cessation of the formation of new peduncles and the shedding of existing buds. If you do not immediately start using lamps for plants or do not change their power, a large lack of light will provoke a complete cessation of the flowering process. Variegated species will lose their colorful color. The foliage will become monotonously green, and in the lower tiers it will dry out and fall off.

Signs of lack of light in plants

When talking about lighting for plants, we must understand that we are not talking purely about the source of its supply, but about the spectral diversity of the light flow, to which, in fact, the flora reacts. The light emitted by plant lamps contains waves of various colors:

• red;
• green;
• orange;
• blue;
• yellow;
• purple;
• ultraviolet.

Red-orange range

The most important colors for plants. They carry the energy charge that is so necessary for successful photosynthesis. In addition, red-orange flows are responsible for the speed of plant growth. If it is necessary to delay the flowering period of bulbous or other types of flowers placed in a niche for plants with lighting for a certain period, it is necessary to increase the intensity of their irradiation with this particular light spectrum.

The red-orange range is most important for plants

Violet-blue range

These colors also stimulate photosynthesis processes. Without their participation, protein is not formed and the plant does not grow.

Having received a dose of blue-violet illumination, plants that naturally live in short days will bloom faster.

Purple-blue lighting for plants

Ultraviolet

Rays with a wavelength in the range of 280 - 315 nm help to increase the cold resistance of plants and also prevent them from stretching excessively. Ultraviolet waves are involved in the synthesis of a number of vitamins.

Ultraviolet helps to increase the cold resistance of plants

Yellow-green range

In principle, this spectrum is not vitally important in lighting for plants, but in combination with other light fluxes it contributes to their harmonious development.

Knowing the meanings of each color range, it will not be difficult to choose a lamp to illuminate the desired type of plants.

When using phytolamps, the main thing is not to disrupt the biorhythm of flowers, so in niches for plants with lighting or in greenhouses they need to be turned on and off at strictly defined times. Experts recommend timing the start of daylight hours at 7-8 hours, and its end at 20-22.

It is recommended to turn on the backlight during the daytime

How long should a phytolamp burn?

After sowing and until the first shoots appear, the lamp is left on for the entire time. After shoot germination, the optimal regime for plants is to observe daylight hours. At 6 am the phytolamp is turned on for 2.5-3 hours. Then the crops are saturated with natural sunlight, after which the lamp is turned on again from 17:00 to 22:00. Then the plants sleep.

However, if crops are grown indoors without access to sunlight or there is not enough natural light, then phytolamps work continuously except at night. Also, when choosing the lighting mode of lamps, the season and weather conditions matter. On cloudy days and winter, the phytolamps are turned on for a longer time.

Useful tips

At any time of the year, green pets will feel great if you give them the opportunity to catch light.

We share useful tips from experienced flower growers:

1. Ordinary mirrors increase the intensity of artificial refreshment. They are installed on the side slopes of windows, which allows additional reflection of the sun's rays.
2. Foil, white glossy fabric and reflectors also provide additional light radiation. They are positioned so that the light is reflected towards the indoor flowers.
3. Tulle curtains placed between the greenery and the room help reflect diffused light. But if you hang tulle between the window and the plants, the intensity of natural light will decrease.
4. Each flower has its own natural biorhythms, and in order not to disrupt the natural process, you need to create a schedule.
5. A universal glow for green pets can be created by installing a matte screen.
6. Illuminating dracaena and other tree-like plants with warm light will give them a compact shape.
7. Proper alternation of day and night will allow plants to be healthy. For this reason, the lamp should be turned on 1-2 hours before dawn and turned off 2 hours after dusk.

Which spectrum to choose

Phytolamps have one spectrum or several at the same time. Such models of phytolights are also called bicolor or multicolor. For plants to grow and develop, they need different light levels.

Multispectral phytolamps operate in three spectra: red, blue and warm white light. They are suitable for growing plants with a thick and dense crown, as well as at the stages of flowering and ovary formation.

Full spectrum phytolamps alternately operate in different ranges with peaks in the red and blue zones. Such phytolamps are excellent for growing seedlings and adult plants indoors without or with insufficient natural light. However, it is worth knowing that in some types of phytolamps their radiation irritates the organs of vision and it is recommended to install them in non-residential premises.

What light is best for growth?

Of course, the ideal light source is solar energy. In apartments with windows facing southeast and southwest, you can grow any flowers, placing them in different parts of the room. But don’t be upset for those who only have a north-facing view from their window. Fluorescent and LED lamps for lighting plants compensate for the lack of sun rays.

Fluorescent lamps for plants are a time-tested budget option. They are suitable for those who are trying to create normal conditions for a flower with little investment. LED phytolamps are for those who want to speed things up and achieve the best results in a short time, despite the price of several thousand rubles.

The meaning of spectrum colors for plants

The blue spectrum is needed for the stages of seed germination, that is, for growing seedlings.

The red glow is necessary in the flowering and fruiting phases. Moreover, for accelerated growth of seedlings, blue and red spectra are used in combination.

Orange and yellow light activates photosynthesis processes and the production of beta-carotene.

Green and blue spectra accelerate the formation of chlorophyll.

Ultraviolet light strengthens plant roots and stimulates the growth of green mass.

Choosing the spectrum of a phytolamp

The purpose of using a lamp for growing plants is to extend daylight hours, regardless of the time of year and the degree of illumination outside the window. However, not all lighting sources are equally good for this; it should be noted that the same lamps will be useful at the germination stage and completely unacceptable for harvesting. There is also a significant gradation between plants that love bright light and those that grow in the shade. Many features are dictated by the latitude zone, in which daylight will differ in accordance with the position of the sun in the sky.

The radiation parameter is measured by the wavelength of light or the temperature of the light glow, which are displayed in the lamp passport. In relation to plants, the spectrum has the following effects in accordance with clauses 2.2.16 - 2.2.18 GOST R 58461-2019:

• 600 - 700 nm - red spectrum, which helps plants set fruit and bear flowers under the influence of the warm spectrum. It has a fairly low color temperature - from 2000 to 3000 K, and is easily implemented with sodium gas-discharge lamps.
• 500 – 600 nm is included in the green or lilac region and represents a neutral option for supporting natural processes.
• 400 – 500 nm – the blue spectrum is used for the development of the stem and leaves of the plant, stimulates the growth and branching of the root system. The range of color temperatures ranges from 6000 K and more.

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3. Influence of spectrum on plant growth activity In practice, linear phytolamps are made with a combination of several colors at once. For example, LEDs of the red, orange, and blue spectrum are collected in a matrix in different ratios.

How to calculate the optimal power of a phytolamp

To do this, you should study the information on the packaging of the phytolight from the manufacturer. To calculate the required power, you need to decide on the type of light culture and, taking into account the planting area for each light culture, its requirements for the power of the light flux at a distance, select the required number of phytolamps of a certain power. The table shows the indicators for each plant type.

Rules for installing the lamp

When installing lamps, you should follow some rules that will help you grow healthy green spaces and not cause harm to them.

Recommendations for placing devices:

1. The light needs to be directed from top to bottom: this is how the sun illuminates the plants - this activates vegetative processes.
2. The lamp is placed at a height closest to the sprouts, but you should remember about possible thermal burns.
3. Avoid getting drops on the light source when spraying: the device can quickly fail.
4. You cannot use side lighting: the shoots will be drawn towards the source and deformed.
5. The use of mirror screens directs the maximum light flux to the plant and at the same time protects the grower's eyes.

The greater the distance from the lamp to the flower, the lower the intensity of the light flux. Exceeding the distance by two times reduces the power by four.

The best option for a device is a design that can be moved. Thus, the lamp can be brought closer and further away depending on the needs of the plant.

Which lamps are not suitable?

Experienced city farmers do not recommend using conventional incandescent lamps. Firstly, they do not provide any benefit in growing plants. Secondly, they emit too much heat, which can damage crops and burn leaves.

Medical devices, lighting equipment for solariums and quartz lamps are not suitable as phytolamps for plants. Not only will they not bring results, they can lead to the death of all plants.

If the packaging does not describe the radiation spectrum or the phytolamp does not have red and blue spectra, then you should also refuse to purchase. There will be no benefit from such an acquisition.

How to make an LED lamp with your own hands

It is not difficult to make an LED device with your own hands.

To do this you will need:

1. Prepared place for placing green spaces and lighting.
2. Install fasteners.
3. Conduct wiring to the lamps.

LED elements are often used as lighting. The reason for this popularity is simple: this type combines two spectrums - red and blue. These lamps consume little electricity, are easy to install and operate, and their cost quickly pays off. The LED strip is easily attached to furniture, shelves or walls using glue.

To make the device you will need:

1. Led elements of two emission spectra.
2. Hot melt adhesive or thermal paste.
3. Material for the base of the product.
4. Power unit.
5. Cord, plug and switch.

When creating such a structure, choose an assembly option based on the level of plant development.

Correct ratio and placement of elements:

1. Each diode emits light in the form of a cone. To ensure that the entire area under the lamp is illuminated evenly, the cones must overlap each other.
2. At the first stage, a two-to-one ratio of elements is made for young shoots: one red diode is taken for two blue diodes. This placement option helps the development of the root system. The plant becomes low with a thick stem and well-developed leaves.
3. The second stage is when the plants need rest: the required ratio is one to one.

When forming an LED device, the elements in the selected sequence are fixed to the base using hot-melt adhesive or bolts. The finished tape is connected to a power supply, cord, plug and switch.

How to properly illuminate seedlings

For maximum effect, phytolamps must be installed above the plants. It is necessary to ensure that the light falls on the plants at a right angle of 90°. If the installation is carried out from the side, then the sprouts, tending to the light, will bend and subsequently break due to the weight of the harvest.

To grow seedlings or plants at home, you should buy a phytolamp with a built-in diffuser. You can build a reflector from shiny surfaces so that sunlight does not go into the room, but returns to the plants. Reflectors are also needed if a phytolamp with a spectrum that affects the human visual organs is used.

Important operational issues

Now let's dwell on the intricacies of using phytolights so that their work is as effective as possible.

If the plants are placed on the windowsill, then to illuminate them you can install base lamps with a round bulb. By drawing up a diagram, you can easily determine the appropriate number and power.

If pots and containers with seedlings are installed on racks and shelves, then linear lamps would be more appropriate. They are similar in appearance to a regular fluorescent lamp and therefore occupy a minimum of space. And the large length of the bulb increases the illuminated area. You can install such lighting above the windowsill.

To illuminate plants in greenhouses, again use linear devices. The only caveat is that here they should be more powerful.

Before you start using a phytolamp when growing seedlings at home, you need to think about the issue of its long-term use. Firstly, different stages of plant development require an individual distance between them and the lamp. For seedlings, the optimal gap is 20-25 cm. For adult plants, it increases to 25-30 cm. Therefore, immediately provide for the possibility of changing the length of the suspension. Moreover, immediately lay it in a sufficient range - after all, the plants will stretch upward.

Also keep in mind that the light zone has an effective (upper) and ineffective (lower) segment. Ideally, the plants should be in the first. However, with each rise of the lamp, the effective segment will move further and further away from the base of the plant. This effect can be neutralized using special lenses.

In order not to harm the plants, you need to figure out when to turn on the phytolamp for seedlings. The optimal time to start additional lighting is the fourth or fifth day after the seedlings hatch from the seeds. There is no point in using a lamp before. Its function is not to warm up, but rather to illuminate, so it will not have any effect on seeds deep in the soil.

By illuminating plants from the very beginning of their development, you prevent possible sun deficiency and help activate the processes of growth and formation. Experiments show that every missed day affects the intensity of the growing season.

Another critically important point is that you need to understand for how long and how often you can turn on additional illumination with a phytolamp for seedlings. Here it is necessary to focus on the quality of natural light in the room and the individual needs of specific plant species. In a dark space without windows, the lamps should work all day long. For rooms with access to sunlight, the intensity of insolation must be taken into account. The more light the sun provides, the lower the need for a lamp.

Average duration of daily supplementary lighting for insolated spaces:

• cabbage of any kind, potatoes, garden strawberries, melon - up to 12 hours a day;
• for nightshade crops (tomatoes, bell peppers, eggplants) – up to 14 hours;
• for herbs and greens – 16-18 hours;
• flower crops – from 16 hours.

Important: the more powerful the lamp, the less time it will take to operate effectively. But don't go for maximum power. Firstly, it is an overspending. Secondly, an overly powerful lamp can burn the seedlings.

How to use a phytolamp

Each grow light comes with instructions for use. It is necessary to correctly calculate the height of the phytolamp suspension, the distance to the seedlings, the required power and the radiation spectrum. If the seedlings look healthy, then all parameters are set optimally.

As the plants grow, it is necessary to adjust the spectrum, power and height at which the phytolamp is located above the crops.

This applies to growing plants on the windowsill and in industrial premises. In the first case, phytolamps cannot be covered with anything. In the second, greenhouses must be equipped with powerful cooling radiators to maintain the required temperature conditions so that the plants do not overheat.

Which is better: buy a ready-made lamp or make it yourself

When choosing a lighting device for house plants, experienced gardeners are faced with a dilemma: buy a ready-made solution or make lighting for plants with their own hands. You should understand this issue and look at the pros and cons of such options.

The finished device is distinguished by a large selection of products in terms of spectral characteristics, price and design.

Advantages:

• the power of the device is selected depending on the area of ​​plantings;
• a quality manufacturer offers products that are safe to use and easy to connect;
• you can choose the optimal design location: on a tripod, hanging type of device;
• ease of use: the height and angle of inclination are adjustable, and the products fit harmoniously into any interior;
• most devices are equipped with a reflector, which makes it easier to perceive unusual radiation;
• the spectra are indicated in the official accompanying documents of the device;
• The devices can be supplemented with a timer to control operating time.

The downside of these products is their high price. Cheap analogues may not meet the stated characteristics.

Let's pay attention to homemade options and consider their advantages and disadvantages.

Pros:

• the ability to select several inexpensive products that complement each other in the color spectrum;
• more economical and energy-saving devices are used;
• the timer can be connected independently;
• Self-assembly saves money.

Minuses:

• Tools are required: soldering iron, tester, screwdriver and others, as well as the ability to use them;
• Knowledge of electronics is required.

Harm of phytolamps to people and animals

For growing plants at home, it is not recommended to use a phytolamp with a power of more than 70 W. Halogen phytolamps are safe for the health of people and animals, but sodium and mercury phytolamps are dangerous due to the vapors of harmful substances they contain. Therefore, at the slightest damage, they must be disposed of immediately.

Preference should be given to high quality phytolamps. Inexpensive lamps do not emit light constantly. Their periodic blinking can lead to irritability, insomnia, decreased performance, visual acuity and headaches.

Also, people and animals should not be exposed to blue and red spectrum for a long time. This is dangerous due to dizziness, nausea, problems with vision, heart and brain. In addition, prolonged presence of a phytolamp in these spectra during operation can lead to fatigue, the development of inflammatory processes and the appearance of burns.

For small pets, the light from phytolamps is useful. The main thing is to use them correctly and dispose of them in a timely manner, then the phytolights will not cause harm to either people or animals.

Which lamp to choose for plants and flowers?

To illuminate indoor plants at home, it is best to use fluorescent lamps with a glow temperature of 6400-6500K and a color rendering index of at least 75, i.e. 765 is marked on the lamp, but 865 is better.

Depending on the number of colors, choose a T8 lamp type with a power of 18W (60cm length) or 36W (120cm length) - these are the most popular options that are easy to find and inexpensive, as are the lamps for them.

• The main thing is to select a lamp for illuminating plants with a higher color rendering index: using osram or Philips lamps as an example: not 765, but 865 or the Lumilux series. The first number indicates the color rendering index: 7 – 70-75 or 8 – 80-82.

And the next two numbers are the color temperature in Kelvin: 40 – 4000K – neutral white light, 65 – 6500K – blue (cold daylight white).

EXAMPLE: OSRAM L 36 W /765 Daylight - 36 Watt (120 cm) T8 - the optimal combination of price and quality.

IMPORTANT! The closer the lamp reaches the end of its service life, the lower its luminous flux becomes. At the end of the service life it is no more than 54% of the initial one.

When working for 12 hours every day, the lamp will work for no more than 28 months. In practice, there is often no point in using a lamp for more than 12 months (5000 hours).

• In addition, use an incandescent lamp so that in addition to the blue color, the plant also receives red waves. The main principle: for 100 W of light from a fluorescent lamp, 30 W of incandescent lamp.

For a lamp 18 W 765 (about 80 W) - 25 W incandescent lamp, for a lamp 36 W (160 W) - 40 W incandescent lamp. This way you can get a better balance of red and blue.

• ALTERNATIVE: LED lamps. For those who can now afford to spend more money on artificial lighting for indoor plants. The amount spent now will easily pay off in the future due to the large resource and low consumption of LED lamps.

Which is the best lamp to buy for plants? Results

BRIEF RESULT: the choice of lamp for plants and flowers, of course, largely depends on the amount we are willing to spend and our goals.

For illuminating plants on the balcony in an apartment and for constant artificial lighting of flowers or seedlings in a greenhouse, different types of lamps are optimal.

The editors of the Flower Festival magazine recommend the following for the average florist:

1. Budget option - OSRAM L 36 W /765 Daylight - 36 Watt (120 cm) T8 fluorescent lamp + 40 W incandescent lamp.
2. The middle option is a fluorescent lamp for plants OSRAM L 18 W / 77 FLUORA - 18 Watt (60 cm), or OSRAM L 36 W / 77 FLUORA - the same, 36 Watt (120 cm) T8 type.
3. The best option is an LED phytolamp for plants LED Grow Light from a reliable manufacturer.

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An example of an Osram fluora lamp

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How can you replace a phytolamp?

In cloudy weather or in cold months with a lack or absence of warm sunlight, nothing can replace a phytolamp. In clear weather, light diffusers will help plants develop. They are made from reflective materials or use mirrors.

You can also buy an LED strip as a homemade phytolamp.

Using double-sided tape or glue, it is attached to the suspension above the plants. You just need to correctly connect the power supply to it and build a plug to connect and disconnect the power supply.

However, such a phytolamp will not bring much benefit. Special equipment for growing plants is complex, and such an effect cannot be achieved on your own.

How to determine that a plant is not getting enough light

Shade-tolerant plants require light levels from 1000 to 5000 lux, and light-loving plants require light levels from 10,000 lux.
You can measure the level with a special device. But if it is not there, and this is usually the case, then the plant itself will tell you when there is not enough light for it. Insufficient lighting affects the appearance of any plant. First, the natural color of the leaves changes: young leaves grow pale and small, leaves with variegated colors (scindapsus, variegated ficus and ivy) lose the brightness of the pattern, sometimes becoming simply green. In many species, the lower leaves turn yellow and sometimes fall off.

In almost all species, shoots are noticeably elongated and bent towards the light. If you compare the distance between leaf nodes that grew in summer and those that appeared in autumn or winter, the difference is very noticeable. For example, in pelargonium, the internodes lengthen by 2-3 times.

An experienced gardener will never wait for his plants to stretch out and begin to lose leaves. First of all, you need to know exactly whether a particular species is shade-loving or needs bright light, which can be found in the encyclopedia of indoor plants. And if there is a suspicion that the house flower is dark, then you should definitely install lamps for illumination.

Many novice flower lovers, having learned about the possibility of using artificial lighting, begin to illuminate plants around the clock. But, contrary to expectations, they languish. In the dark, plants also undergo processes necessary for life. Regular alternation of day and night is important. The flowering of many species depends on changes in these periods.

How to increase illumination

When looking for a place for a lamp, remember an important rule: illumination decreases greatly with distance. By doubling the distance between the lamp and the plant, we will give it only a quarter of the original amount of light. Lighting is most effective if the rays fall on the illuminated object perpendicular to the surface. Since the leaves of most indoor flowers are located horizontally, the source should shine as strictly from top to bottom as possible.

There is a way to significantly increase the illumination of a surface while maintaining all the parameters of the light source. Using a reflector allows you to increase light output by up to 50%. The principle of operation of this device is to reflect upward and sideways light from the lamp down to the plants. Point light sources (incandescent, energy-saving and gas-discharge lamps) are most often equipped with a conical or elliptical reflector, and fluorescent tubes are U-shaped. White matte surfaces reflect light best, not mirrors, as we used to think.

Often reflectors are provided with lamps in which a light source is installed. For halogen incandescent lamps and high-pressure discharge lamps, the reflectors may be contained in the bulb itself. You can make a simple reflector yourself from foil and tin. But remember that it must be fireproof and provide for heat removal from the lamp.

You can complete the creation of a home artificial light system using electric timers, designed in the form of an adapter: the device is plugged into an outlet, and the lamp cord is connected to it. A timer with a mechanical programmer is much cheaper than an electronic one, but is not as easy to use. The latter's microcomputer allows you to program the lamp on/off with an accuracy of up to a minute for a week or month in advance, and you can set different lighting modes on different days.

When choosing a light source, pay attention to the type and electrical power of the lamp - they determine the intensity of the glow. The color richness of the spectrum is also very important: for successful growth and flowering, plants need the red and blue components of sunlight. The human eye is adapted to perceive yellow and green rays. A bright lamp, from our point of view, may well turn out to be dim for an indoor flower or seedling.

Lighting characteristics are presented in the table below (

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