Growing Indoors: What Does Full Spectrum Grow Light Means

Growing Indoors: What Does Full Spectrum Grow Light Means

When purchasing an LED grow light for your plants, you’ve probably seen different terms used to describe the light. Full-spectrum is a common term that is typically associated with natural sunlight. But, what does full spectrum grow light mean really? And how is it beneficial to plant growth? 

This articles answers all your questions and more on full spectrum LED grow lights. This way, you can make an informed decision with your next purchase. 

What Does Full Spectrum Grow Light Mean?

First, let’s unpack what spectrum means. Spectrum refers to light’s electromagnetic wavelength that can help promote plant growth. Visible light wavelengths have a color associated with them that ranges the standard colors of the rainbow. 

The term photosynthetically active radiation (PAR) refers to the spectral range or waveband that plants can use in the process of photosynthesis. This generally corresponds with visible light. However, there are also non-visible wavelengths, such as ultraviolet (UV) and infrared (IR) light that have proven helpful for plant growth. 

A full spectrum grow light means the light emitted from the LED closely resembles natural sunlight that includes all the different spectrum wavelengths. This means the LEDs produce an output of a broad, significant, continuous light across most of the PAR range. Some full spectrum LED grow lights also include UV and IR light. While you can’t completely mimic sunlight, having a broad range of wavelengths allows you to use balanced light spectrums to your advantage when growing. 

Full Spectrum vs. Traditional Red/Blue Spectrum LEDs

Traditional LED grow lights typically combine blue and red LEDs producing a purplish-pinkish light. They are usually referred to as narrow bands of light and are monochromatic LEDs, meaning there is a red LED and blue LED. Only red and blue light were traditionally used because it was found plants perform photosynthesis effectively when provided a combination of these two parts of the light spectrum. 

In contrast, full-spectrum LEDs have a broad light spectrum band and are more similar to natural sunlight. This broad spectrum or wider range of colors makes the light appear “white.” However, not all white LEDs are full-spectrum. Some manufacturers coat a blue LED with a mixture of yellow, green, and/or red phosphors to increase the wavelength. This results in a “white” light appearance.  

What is the Best Light Spectrum for Plant Growth? 

As previously mentioned, traditionally, plants have been known to grow effectively with a combination of red and blue light. The red light encourages stem growth, flowering, and fruit production. The blue light encourages intense photosynthesis and vegetative growth. 

However, the truth is there is no such thing as the best light spectrum for plants. Every plant varies on how much light they need to thrive, so the ideal spectrum will vary at the plant’s growth stage and the type of plant. 

Generally, plants do best when provided light of all wavelengths, but they don’t need the same amount of each wavelength. Research is increasingly finding that a balanced spectrum works best for plants since they evolved using natural daylight. 

Pros and Cons of Full Spectrum Grow Lights 

Since sunlight is complex, full spectrum grow lights aren’t as dynamic as natural sunlight. Some products also aren’t customed tailored for rigorous plant growth. It’s normal to wonder if the extra price tag is worth the full spectrum product. For most growers, it is. 

There are still various benefits to letting your plants receive the closest similarity to natural sunlight, especially if they are indoors. Full spectrum LED grow lights can:

  • Be tuned for a balanced wavelength for each stage of plant growth 
  • Mimic natural sunlight that helps trigger plants to flower
  • Increase yield with healthier plants
  • Give you a wider range of adjustable features depending on your type of plant

Choosing the Best LED Grow Light 

Now that you have a better understanding of full spectrum grow lights, what other features should you be looking out for when making a purchase? First, you want to get to know your plants and understand the set-up of your operation. 

For example, suppose you are growing plants in a greenhouse where natural, outdoor sunlight still reaches the plants. In this case, it could be effective to use only traditional LEDs. For indoor growers, having a full-spectrum LED offers your plants the additional benefits of the broad spectrum of lights. 

You can also purchase affordable full spectrum grow lights that have:

  • Optional light spectrums for future needs
  • Dimming functions 
  • Spectrum tunable functions
  • Daisy chains for multiple LED set-ups 

Whatever your final decision is, make sure it aligns with your budget and plant’s needs. 

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About the author

George Mouratidis works as a full-time copywriter and journalist. He is the founder of, a bespoke content writing agency for the cannabis industry. George is a regular editor for many industry publications, as well as corporate blogs. He is also the co-writer of the book Ganja Hustle; a hit cannabis growing guide for the USA and Canada markets. When he is not writing, George likes to work out, trying new foods and playing with his cat. Currently, he lives in Greece.