Illuminating seedlings at home

Illumination of seedlings - when and how much to illuminate

When highlighting plants on the windowsill, it is important to follow certain rules. Without doing them, you can hardly expect a positive result. And sometimes breaking these rules can lead to fatal consequences.

With a huge abundance of lamps that are used to illuminate seedlings, it is important to calculate their number. And for this, first of all, they focus on the power of the lamps. For example, for the sprouting of tomatoes, eggplants, peppers, and cucumbers, an average of 200 v per 1 sq. m is required. m.

For example, if you have a window sill with an area of approximately 1 sq. m, then you need to hang 2 light bulbs with a power of 100 v.

Light sources should be located no closer than 20 cm from the topmost leaf.

Now, for the full development of seedlings, there are phytolamps on sale that emit red and blue spectrum of rays. It is with this lighting that the metabolic process is stimulated, the production of chlorophyll increases and photosynthesis accelerates. Fluorescent lamps have a wider spectrum of rays, but there are nuances when choosing lamps. Which one to choose will be discussed in more detail later in the article. But it is better not to use ordinary incandescent lamps, which are still available in some places. They have a high heat transfer, and this increases the risk of leaf burn and causes drying out of the soil.

There are 2 rules for duration.

It is not necessary to illuminate the seedlings around the clock, since the “day-night” period must be observed. You can allow 24-hour lighting for two weeks after emergence. But later there should be no more than 8-12 hours of daylight. The exception is slow-germinating seeds (leeks, celery, etc.), they need additional lighting up to 16 hours a day.
Short winter days are usually cloudy, so the lamps will have to be turned on even during the brightest time of day.
Regardless of whether you highlight the seedlings or not, the best option for placing the boxes is on the southern windows.

Additional light for tomatoes

Additional lighting for tomatoes is an important condition for a rich harvest. For garden crops, illumination of 20-40 thousand lux is required. But in February-March, when the first shoots appear on the seedlings on the windowsill, the illumination is only 5 thousand lux even on a sunny day. Now it’s easy to calculate how much light tomatoes need.

How to use phytolamps at home

All plants on Earth are adapted to life under the sun. The sun emits the entire spectrum of rays (red, orange, yellow, etc. - remember the saying about the hunter), that is, all visible rays. At the same time, in order to start the process of photosynthesis and plants begin to use these rays, the plants must be irradiated with photons of the red and blue spectrum. Manufacturers use this fact to produce phytolamps.

Today manufacturers offer 2 types of lamps:

round - in the form of a disk with LEDs built throughout its entire diameter;
linear - in the form of a tubular lamp with lighting elements inside.

Phytolamps emit rays in the range necessary for the plant, without spending energy on producing light in the “unnecessary” part of the spectrum. They contain a predominant red and blue spectrum of rays, which is exactly what plants need. They are convenient for lighting seedlings that stand on a table or windowsill. It is better to use phytolamps with the Bicolor spectrum, that is, with a combination of red and blue rays, it is the most optimal for young plants. And the spectrum of Phlox-2 is quite white, and it is more suitable for indoor plants.

The most common version of phytolamps is the one designed for a regular cartridge. It can be hung by a hook to the shelf of the rack, on a hook or bracket. The distance from the lamp to the plants should not be more than 70 cm - 1 m. The higher we raise the lamp, the greater the radius of illumination will be, but at the same time the concentration of light will be less. The phytolamp is installed so that all the rays from it fall only on the plants and do not run down to the floor. Although, if you remove the lenses from the lamp, the illumination radius will increase from 60º to 120º; such a lamp can be hung higher.

This lamp is not suitable for lighting seedlings on racks. In this case, it is better to purchase linear lamps, which contain up to 24 LEDs with a power of 50-75 v.

We calculate the power and number of lamps

First of all, the performance of the lamps - the amount of luminous flux and the illuminated area - depends on this indicator. In addition, the power is used to calculate at what height the selected phytolamp should be hung above the seedlings being illuminated:

A 36-watt lamp at a distance of 1 meter from the plants creates an effective light zone with a diameter of about 80 cm.
15-watt models should be placed at a height of approximately 35-40 cm - in this case they will create a light spot with a diameter of 45-50 cm.
Low-power 7-10W light bulbs should be mounted at a level of approximately 20-30 cm above the window sill mini-plantation. The diameter of the effective lighting zone they create is approximately 30 cm.

The number of phytolamps is determined in such a way that all plants fall into the illuminated area. To simplify the task, you can make a diagram. Keep in mind that the circles of light do not have to intersect. If, when distributing the backlight according to the scheme, minor gaps remain uncovered, then it is better to leave them. Each additional lamp in the system means additional money. And plants that will be exposed to light from two lamps at once may be damaged by this.

On average, one 15-watt lamp is required for every 50 cm of window sill.

Illumination of seedlings with fluorescent lamps

Seedlings can also be illuminated using conventional fluorescent lamps; they are less voracious in terms of energy consumption, do not dry out the soil in the boxes, are relatively cheap, and will last longer. Fluorescent lamps can be linear tubular from 45 cm to 1.5 m. Or compact with a standard base that can be screwed into a regular lamp body. It is better to use E27 lamps.

The emission spectrum of luminescent rays is much wider; it contains a white spectrum. Pay attention to the light temperature (numbers in thousands), it is indicated on the base. These indicators indicate which spectrum of rays predominates in the lamp. And we remember that the red-blue spectrum is important for seedlings. Please pay attention to the following points when installing.

If the numbers are small - 2500-2700, this is very good, the spectrum of rays will lean more toward red.
The numbers are large - 6300-6500 - this is also good, the spectrum will be quite cold and blue.
The worst option is when the number is written - 4000. But even with this indicator, there will be no harm to the plants within 12 hours.

If you decide to use fluorescent lamps, choose ones with a pink-violet glow.

The blue spectrum stimulates cell division in plant tissues, and the red spectrum activates growth and promotes the formation of flower buds.

Long fluorescent lamps are very convenient to use for illuminating seedlings on racks. Many gardeners, judging by the reviews, of course choose those that are cheaper.

LED strips - how to use at home

LEDs are a modern material that is now often used in everyday life and in production for additional illumination. They are especially effective for lighting shelving without heating the air around the plants. They can be bought at a regular hardware store or ordered from online stores. They are not expensive, but with a power supply they will be a little more expensive, but there will be no problems with hooking it up.

For optimal illumination of seedlings, alternating 2 red LEDs and 1 blue is recommended.

Advantages of LED strip:

They are inexpensive, affordable, and their price quickly pays for itself.
They emit red and blue spectrum rays.
They consume a minimal amount of electricity.
Easy to install.
They illuminate a fairly large area.
They don't heat up.

To make a lamp, you do not need any special knowledge. It can be made from an aluminum profile onto which a tape is glued like a snake, which has an adhesive base on one side. In doubtful cases, you can also glue it with Moment glue for strength.

Which is better for illuminating seedlings - fluorescent or LED lamps?

What lamps are best to choose for supplementary illumination of seedlings? Here it is necessary to compare efficiency, operating time and price.

By price:

the cost of a phytolamp starts from 2-3 thousand rubles and more, depending on the manufacturer and modification.
Fluorescent lamps cost from 50 rubles and above.
LEDs - from 33 rubles per 1 meter.

Operating time:

The LED, as sellers assure, can burn forever until it goes out completely. But over time it fades. This is due to the presence of impurities in the crystal, which change its structure over time. This results in some of the energy being converted into heat rather than light. Therefore, the service life of the tape is usually considered when it fades by 30% of its original state.
The lifespan of the phytolamp is up to 3 years. Induction lamps can last up to 15-20 years with 10-12 hour operation.
Fluorescent lamps. The reserve is 16 thousand hours, however, by the end of this period the power drops noticeably.

In terms of efficiency , all lamps are almost equivalent, so when choosing them for illuminating seedlings, be guided by the above characteristics.

Of course, nothing can replace the sun. And to give your plants even more sun on sunny days, make reflective screens from white paper, food foil or foil foam, which is usually used as insulation.

How to make seedling lighting with your own hands

To provide additional lighting above the seedlings, you need some kind of structure to which lighting fixtures can be hung or attached. This video shows how you can make such a stand using simple materials at hand.

When there are a lot of seedlings, but there are few windows, or some of them are cold, you can build a backlit rack to save space. How to do this, watch the video.

To summarize what has been said, it should be noted that now few people grow seedlings the old fashioned way, simply by placing boxes on the windowsill. Experienced gardeners try to extend daylight hours for plants and use various lamps for this. But both the quality and potential of plants depends on correctly selected lighting. And if you follow all the rules, light feeding will serve as an additional guarantee that the seedlings will eventually grow strong, healthy and will be able to move to a new place without any problems.

Have a good harvest!

Common mistakes gardeners make

Most often, when additional illumination of tomato seedlings, gardeners make the following mistakes:

If burns form on the foliage of seedlings, this means that the lighting fixtures are located too close to the seedlings.
The foliage becomes faded and the shoots become elongated if the lamp is installed much higher than necessary or it has insufficient power.
If the lighting fixtures are installed on the side, the shoots of the plants may bend towards the lamps. In this case, they must be moved upstairs.
Using simple incandescent lamps for additional lighting does not give the desired effect, because their light is completely useless for plants.