Light for plants

Plants need light to make photosynthesis, an essential process for their life. It is therefore important for your plants to flourish that they can benefit from a light source that meets their needs. So, what light should we give our plants?

The best source of light for plants would be sunlight, because they have evolved for thousands of years under its rays and are therefore adapted to it. Unfortunately, when growing indoors, it is not always possible to take advantage of the sun. This is how many brands have designed products allowing the development of plants in their vegetative phase as well as in their flowering phase.

In the rest of this article, I will focus more on light artificial for plants, through three parts: the color of the light spectrum, how to choose your lamp and finally calculate the electricity consumption of your lamps.

THE COLOR OF THE LIGHT SPECTRUM

Plants absorb more blue and red wavelengths to carry out photosynthesis. Specifically, blue wavelengths promote growth (vegetative phase) while red wavelengths promote flowering (flowering phase).

The light spectrum of the sun emits all wavelengths, if you use natural sunlight you don't have to worry about this. On the other hand, if you use horticultural lamps, make sure that they emit blue and/or red wavelengths depending on your needs. It is thus possible to move towards monochrome, violet or white spectra, because the latter include all colors.

There is a unit of measurement called “Kelvin” to determine the various shades of white. The scale goes from 1000 K (warm white) to 10,000 K (cold white) through all shades of white.

Below you will see an example of the white light spectrum, corresponding to a 3000 K lamp and a 5000 K lamp from Bionicled .

Until now, I used lamps with these two spectrum colors simultaneously to benefit from the benefits of each on my crops. Currently I am testing the brand new Bionicled lamp, the BionicBar Max, which has a light spectrum of 3500k, the balance between the two spectrums above.

 Especially blue tones will favor growth and red tones will favor flowering.

 

CHOOSE YOUR HORTICULTURAL LAMP

There are different types of lamps, spots, bars and panels.

THE spots are to be used for small growing areas and can be used in many commercial lamps and floor lamps. If necessary, if the base size does not match, base adapters are available. THE bars are perfect for straight spaces, like shelves. Finally, if you have a large area to cover, such as a growing table or a greenhouse, you can go for panels .

What you need to remember is that the choice of equipment will depend on the shape and size of your crop.

PLACEMENT

The most common is to place your lamps above your crops, and there are several ways to hang them: with hooks, clamps or even with magnets. This is what I do in my greenhouse, I have two bars suspended on the central frame which makes the roof of the greenhouse, using serflex.

It is also possible to place the lamps in front of your growing surface, this is what I did with my display cases to make the most of the space inside the display cases.

Concerning the distance of the lamps from the plants, this will depend on the power of your lamps, the needs of your plants, but also the exposure time. I advise you to start with a distance of 50 cm between the plants and the lamps and adjust by observing your plants. We advise not to place the lamps less than 25 cm and no more than 80 cm from the plants.

POWER CONSUMPTION

An important point with artificial lighting is the electricity consumption and therefore the cost of using the lamps.

A simple calculation will allow you to know what your lighting costs you per month (I did a Excel file which you can use to make this calculation).

You need these 4 pieces of data to calculate electricity consumption:

• The power of the device in watts
• The number of hours per day the device is on
• The number of days per year the device is used
• The cost of the KwH of your electricity contract

First of all, you need to do the following calculation:

[number of hours of use] x [number of days of use] x ([device power in watts] / 1000) = number of kWh

Then all you have to do is recover the price per kWh from your electricity contract and then do the following calculation:

If you divide this result by 12 you will get the monthly cost. For example, a Bionicled spotlight consuming 20 W and being lit 7 hours a day, 365 days a year, consumes 51.1 kWh per year. With a unit price per kWk of 0.1920 € , the consumption of a spot costs me around 10 € per year, less than 1 € per month.

To conclude, put some sun (even artificial) into the life of your plants.

 

PARTNERSHIP

For some time now I have had a paid partnership with the brand BionicLed from whom I obtain horticultural lamps. To benefit from 5% discount on your order, use the code BOTANIST5 !

I hope you enjoyed this post and found it useful! 🙂 If you have any questions, don’t hesitate to ask them in the comments below.