How much space does a photon illuminate

What light do plants need to grow?

Hardly anyone will try to grow a plant in the dark. The fact thatPlants need light to grow, so makes sense. However, lighting conditions can vary or be varied and thus the question that we want to investigate in this article arises:What light do plants need to grow?

Contents overview

Basics of photosynthesis, growth and light requirements

Roughly speaking, photosynthesis takes place in such a way thatPhotons of certain wavelengths from the color cells in the leaves - predominantly chlorophyll - are absorbed. Your electromagnetic energy will be thereconverted into chemical energy. This process is called the light reaction.

With this chemical energy the plant can nowproduce high-energy, organic compounds and use them as building materials or other energy. In doing so, it builds up new leaf cells, flowers, fruits, roots, etc. However, this process is only really started whenas soon as photons hit the color cells.

Plants are pretty picky, though. Depending on how much, how long and which light hits them,their growth is different. Many experiments have already proven that certain light settings affect theIngredients of leaves and fruits of the illuminated plants impact. We will now clarify what the intensity of the light, the duration of the lighting and the properties of the light is all about.

The right light intensity and lighting duration

A tall plant that - let's say - is native to the Mediterranean region has oneother light needs than shrubs that tend to settle in the undergrowth of European deciduous forests. If you want to grow plants or light them artificially, you have to know exactly whether they are more of a fanfrom direct sunlight or shading are.

The lighting duration is clarified relatively quickly. What works best is what has worked well for thousands of years:the conventional day-night cycle, easy with artificial plant lightingto simulate by a timer. With some advanced lights, you can even program a slow sunrise and sunset.

It is worth taking a look at the light intensityso-called photon flux density. More precisely, it is theDensity of the photons of photosynthetically active radiation.

The unit for this is abbreviated in PPFD and in micromoles per square meter and second (μmol / m2s) measured. Direct sunlight has up to 2,000 μmol / m2s.

However, even in the wild or with natural plant lighting, it is very rare that such a high density of photosynthetically usable photons actually hit the plant cells.Plants do not need such high intensities at all.As an average guide value of theA light intensity of 600 μmol / m is suitable2sgood for artificial plant lighting.

Light color and spectrum

When it comes to light color, things get a bit more complex. As is well known, light is onPart of the electromagnetic radiationnamely inWavelength range from approx. 380 nm to 750 nm. That is the part that is visible to humans. It also roughly coincides with the section thatuseful for photosynthesis is.

So let's bring the colors into play. A specific oneLight radiation can be composed of different wavelengthsand thereby gets a certain color. If the wavelengths are rather high-frequency, it is the bluish part of the light spectrum, long waves are more likely to be located at the reddish end.

Thefor us green-looking wavelengths. If these meet chlorophyll cells, they are largely reflected. Therefore, most of the plant leaves also appear green. The so-called green gap results from this phenomenon. If a plant is irradiated with this wavelength, it happensless photosynthesis as the plants do not absorb them as wellcan.

Many manufacturers of artificial plant lighting are now switching to omitting the green wavelength components and all in oneMixture of blue and red LEDs to illuminate. However, this is just as counterproductive as thePhotosynthesis does not completely stop in this area. Due to carotenoids in the foliage, the blue-green, shorter-wave radiation is definitely absorbed and green light is also photosynthetically active, especially with dark green leavesa trace of the green gap just mentioned so.

The LED plant lighting should therefore ideally in terms ofLight spectrum designed evenly become. There are LED lamps with SMD technology that allow the spectra to be mixed. In this way, your plants are supplied with light in all the required wavelengths.

Artificial plant lighting: what kind of light do plants need?

Artificial plant lighting is a complex area. There are innumerable types of light sources and thus optimization possibilities. Every single plant can get exactly the lighting it needs.But which luminaires can be used to generate exactly the light that plants need to grow?

LED in plant lighting

Meanwhile, many LED lights have proven to be thehighest quality solution for plant lighting exposed. They are mostly located in the higher price level. But you also get something for your money:

  • High efficiency with low power consumption
  • Continuous spectrum
  • a long service life depending on the type of LED
  • Choice between different color temperatures
  • The latest SMD technology for LEDs also offers maximum efficiency in terms of light output. Sets with 300 or 400 watts are suitable for areas of 100x100 or 120x120cm etc. With special DIY kits you can build your own LED lamps. Find your LED lamp with our area advisor now.

Sodium vapor lamp (HPS) - already yesterday?

There is something like a competitive relationship between LED lights and sodium vapor lamps. For a long time, the lamps, which are also known as HPS for short, were thatThe ultimate among luminaires for artificial plant lighting. Partly for good reason:

  • Cheap purchase
  • Good results in the flowering phase (spectrum in the yellow-red area)
  • However: high energy losses due to strong heat development

They are now used in many areasreplaced by the more efficient LEDs. These are much more expensive to buy, but the investment pays off due to the longer service life and better results. Sodium vapor lamps are still not completely obsolete, but the LED is definitely on the overtaking course.

Daylight lamp for plants

As the name suggests, a daylight lamp imitates the daylight of the sun. Originally such a lamp isnot specifically for plant lighting, but intended for a more natural lighting of living space.

If you do not place too high demands on the light for the plants, a standard daylight lamp can be sufficient. You have to be aware, however, that this variantnot designed for plant lighting purposeshas been. Thus, a daylight lamp does not necessarily provide the light that plants need to grow. You risk electricity consumption that misses the target.

Energy-saving lamp as a plant lamp

The same applies to the energy-saving lamp. They are known as room lighting and the idea of ​​converting them as a plant lamp is in the room as quickly as you can operate the light switch.

However, the concept of the conventional energy-saving lamp also shootspast the purposes of plant lighting.

There it ismore advisable to use LED plant lighting. Due to the low power consumption and much higher efficiency, definitely come heremore watts in the form of usable photonsin the plant cells.

In addition, energy-saving lamps (like fluorescent tubes, by the way) contain mercury, which is dangerous if handled carelessly and, of course, is not unproblematic in terms of disposal.

In which cases do plants need additional light?

Roughly speaking, plant lighting is needed wherever the plants are too shaded to get enough light. To guarantee growth and a healthy plant,Plants need extra light, especially indoors. We present three specific application possibilities.

Growing young plants: light requirement when sowing

As a hobby or professional breeder, you may be confronted with temperatures that are too cold and too little sunlight most of the time when youstart growing young plants in spring want. After all, there isn't an infinite amount of space on the windowsill. But now especially light germs (in contrast to dark germs)even in the seed stage already sunlightto form seedlings.

In such cases, the growing station is often moved to the basement or other rooms that offer a lot of space. There you will then use plant lamps to ensure thatyour seedlings get the light they need to grow. You can then place the healthy young plants in the bed immediately after the last frost, instead of only then starting with the sowing.

Plants overwinter with LED light

The winters are usually not exactly mild in this country and most cultivated plants do not survive the frosty temperatures and the reduced sunlight. In the interior, however, it is warm andbright enough with the right plant lighting. Your non-winter-hardy plants get enough light and warmth in winter to be able to continue to grow.

Lighting for living room plants

SomePlants make themselves in living rooms especially good. But maybe they are used to full sun instead of darkened lighting conditions in the room. A plant lamp can also be used here.The plant gets the light it needs to grow and you can continue to look forward to beautiful growth and magnificent flowers.

Recognize lack of light: these are the signs

Horny growth:When a plant notices that it is too dark, it tries to get where there is light. Usually the direction is then as high as possible in order to grow beyond shadow donors.This behavior is known as horny growth. The plant grows very quickly, but alsovery long and unstable.

Loss of buds and leaves: In addition to the horny growth, it can also be that the plant simply loses its buds and / or leaves. The leaves first turn yellow and then simply fall off.

If these two signs can be seen, one should take care of a light supply as soon as possible.Does the plant get the light it needs to grow, you may still counteract the unwanted growth behavior and have a stable, healthy plant in front of you again.

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