Sufficient light is important for the health and growth of plants. However, there is a serious lack of light for our houseplants in our homes, especially in our northern regions. Most of them come from brightly lit places like the tropics and deserts, at least for anything currently in the area. You need to understand that there is a huge difference in light outward, even if our house appears very bright to us. On a cloudy day, we find outside lighting around 15,000 lux (unit of brightness) while looking at a well-lit house around 500 lux! This means that even tropical rainforest plants that grow in the shade of tall trees enjoy infinitely more light than our house lighting. For this reason, artificial light is often essential if our indoor plants are to thrive, instead of vegetating in semi-dormancy from September to March! A little theory will help us understand the process.
What are artificial and growing lights?
It can be used in addition to natural light, depending on the number of hours of sunshine that the plants are missing, or as a single source of light. However, not all artificial lights for plants are created equal. These have 3 types of photoreceptors (photon receptors, elementary light particles):
- Those that are sensitive to red light (phytochromes) are the most versatile: they are used, among other things, for germination, the formation of chlorophyll and flowering.
- Those who are sensitive to blue light (phototropin) adjust the “shape” that allows more and more light to be captured.
- Those who are sensitive to blue and ultraviolet light (cryptochromes) have an effect on the growth of stems and leaves, on the flower …
Every color has a wavelength, plants perceive red and blue tones and therefore use the waves emitted between 445 and 750 nm (nanometric wavelength). The human eye perceives colors between 400 and 750 nm. Good artificial light for indoor plants must therefore emit these wavelengths in order to be useful for their photosynthesis.
In addition, the need for this or that light depends on the stage of development of the plant: they are more likely to use blue light when they are in the growth phase (between 400 and 500 nm) and more likely to use red light when they are growing. “They are in their prime (between 620 and 780 nm).
Let’s look at different types of grow lights:
Fluorescent lights are efficient and reasonably priced and must be selected based on your needs. They provide quite good lighting for indoor plants. These lamps are in fact neon, adapted in the shape of a light bulb. They have a low energy consumption.
Energy-saving grow lights are lamps in garden centers that have been specially developed for plants because they offer them the light spectrum that is right for them. They consist of a compact fluorescent lamp, a reflector and a switch. This reflector illuminates the entire surface of the foliage and focuses the light on the plant.
The cool white color (cold white, therefore with blue) is the most efficient for development and foliage, while the warm white (warm white, therefore with red) favors flowering.
One of the most common systems for lighting indoor plants is the LED. LEDs provide a light that is very close to natural light. They do not heat up and have an extremely long service life. In addition, they use practically nothing. Aesthetically, they fit into any interior. They are very effective for both houseplants and seedlings, offering up to four times more growth than growth under fluorescent lights. Horticulture has also confiscated them LED grow lights Promoting the growth, flowering and fruiting of plants.
Led grow lights can also be declined in all colors of the spectrum, in this case blue and red only for plants. You can find LED grow lights, flowering lights, mixed lights that usually provide 80% red light and 20% blue light to the largest number of plants to match and customizable.
How are indoor plants kept under artificial lighting?
Plants that are used to natural light have to adapt to artificial light and need some time to do this – at least a few weeks, sometimes a few months. So you shouldn’t worry too much about this adjustment in the first few weeks of autumn when the plants come back. It is also understood that not all plants come from the same environment. Tropical plants live in an environment where there is almost the same amount of light all year round. However, this is not the case with other plants that come from winter environments and therefore need a period of rest. It is better, depending on the plant, to leave them semi-dormancy for longer or shorter periods, which means less light, no fertilization and little watering.
The best artificial lighting systems
Whichever system is chosen, it must cover the entire surface on which the plants are located with light, have a reflector that directs the light onto the plants, and emit intense light.
There are three systems outfitted with the best of LED grow lights, neon lights, and incandescent lights:
- An LED lighting system is by far the best possible lighting for indoor plants. In addition, these systems are generally more aesthetic. There is now neon typeLED grow lights This is particularly suitable for people who have a lot of plants or who are making seedlings. Plants under LED light grow four times faster than under a neon system and incomparably more than under an incandescent lamp system.
- Second, neon systems are very effective, but far behind LED lighting systems. Oddly enough, systems equipped with only cool white fluorescers were found to be more effective than systems equipped with both traditional cool white and warm white. For maximum efficiency, neon lights should be replaced at least every two years.
- Unsurprisingly, incandescent systems have proven to be very underperforming.
Which lighting for which houseplant?
Indoor plants do not all have the same needs, and these are determined by their natural environment: for example, cacti live in deserts; they need as much sun as possible; Ferns, on the other hand, live in forests, the light is strongly filtered by the trees.
Plants that love light
They will provide around 16 to 18 hours of light per day for those of your houseplants that are in high demand. Not all of them have the same taste, however; there is:
- Those who like direct sun, which is therefore placed near a south-facing window, such as ficus, beauharnais or phoenix, as well as succulents or carnivores;
- And those who prefer western exposure, very bright but without sun or at the very end of the day when it’s softest: Spathiphyllum, Cycas, Schefflera for example.
Plants that prefer partial shade
Plants with green foliage are generally less greedy; Give them an average of 12 to 14 hours of daily lighting.
If our budget allows, it is clear that we should prefer a system with that best LED grow lightsAs these lamps do not heat and use little energy, they are therefore more economical.