Horticultural lighting: which one to choose for indoor cultivation?

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Horticultural lighting: which one to choose for indoor cultivation?

When growing indoors, one of the most important things to give your plants is a sufficient light source, it is this which ensures the process of photosynthesis. Additionally, the size of your space and the type of plant you intend to grow determine the horticultural lighting system and light output you should use. We are therefore going to present these different horticultural lighting systems to you.

High Intensity Discharge (HID) lamps

High intensity discharge lamps are the most widely used in horticulture, they consist of:

  • a bulb: either metal halogen (MH) or high pressure sodium vapor (HPS)
  • a ballast : which serves as a voltage regulator.
  • a reflector : which allows the light to be evenly distributed in the culture space and thus limits the loss of energy.

So there are two types of HID bulbs, and each has its own use. Here is a small diagram to allow you to see it a little more clearly.

Diagram of the visible spectrum of light

Metal halogen bulbs (MH)

MH bulbs have been around since the 1960s. They produce light in the blue part of the visible spectrum.

MH bulbs are mainly used for vegetative growth. That is to say just after the germination phase in order to produce beautiful and wide leaves and also to avoid the stretching effect of the plants.

High pressure sodium vapor (HPS) bulbs

HPS lamp

HPS bulbs were invented in 1964. They produce light in the red/orange part of the visible spectrum.

They are mainly used for the flowering stage. That is, the time when the plants begin to flower and produce the first fruits.

MH and HPS bulbs are not excessively expensive to buy, it is moreover horticultural lighting that produces the best light intensity. However, they generate a lot of heat and therefore require a large amount of energy to operate. It takes about 400W of power for a space of one square meter.

Compact fluorescent lamps (CFL)

CFL lamp

CFLs or compact fluorescent lamps produce blue light, perfect for seedlings and cuttings. They emit little heat, which creates good conditions for the first stages of the life cycle of plants.

Here, the ballast is integrated into the lamp, perfect for very small grow spaces.

However, they do not generate enough light output to provide an effective lighting solution beyond the vegetative stage in some cases.

To get a CFL lamp, it’s here.

LED lamps

LED lamp

LED is a relatively recent horticultural lighting for indoor cultivation and was invented in the 20th century. It is made up of a multitude of diodes which, once connected, produce light.

Many LED lamps provide a violet color light and offer 3 different brightness intensities:

  • For growth with a dominant blue color
  • For flowering with a dominant red color
  • Mixed with a perfect balance between blue and red

But you can also find full spectrum LED lamps that are white light.

This horticultural lighting offers a light output similar to HID for a much lower consumption. Indeed it produces much less heat, so it is suitable for any type of culture.

You want to buy an LED lamp, come here.

Plasma lamps

Plasma lamps are the most recent in the world of horticultural lighting and there is currently little study on this subject.

They would provide an adjustable output that can produce power from 100W to 1300W. That is to say that it would be possible to use this horticultural lighting for any type of plant, in any type of growing space. These lamps would be very energy efficient. In any case, many users claim that they are much more efficient than HIDs in providing a more complete and continuous spectrum of light.

Summary diagram of the different horticultural lighting systems

Some examples of cultivation under horticultural lighting

Evolution over 4 days of a lettuce grown under an LED lamp

Find our article: “ Lettuce cultivation with the Kratky method ” to find out how we proceeded.

Tomatoes grown under HPS lamp.

The tomato being a very greedy plant in terms of luminosity, it is important to offer it a high luminous power such as the HPS lamp. Here, a tomato plant grown with a DWC system under an HPS lamp. To learn more about growing tomatoes, check out our article on “ Growing Tomatoes Indoors ”.

Landes pepper grown under LED lamp

Chilli is also a plant that needs light. Choose sufficiently powerful horticultural lighting to cultivate it. To learn more about this culture, find our article “ Culture of chilli in hydroponics ”.

Parsley grown under an LED lamp

And finally, a stalk of parsley grown under an LED lamp. Learn more about “ Growing Parsley Hydroponically ”.

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