The Power of Adjustable Spectrum LED Grow Lights

Growers are shifting to adjustable spectrum LED grow lights as spectrum control allows control of a plant’s growth life, from seeding to fruiting. 

Additionally, it eases a grower’s job as you don’t need to replace the LEDs at each growth stage as you do with fixed spectrum LEDs. 

However, as the technology is still new, many growers lack the technical knowledge to make the best of it. 

Today’s article delves into the world of adjustable spectrum LED grow lights to help you figure out the best grow light option. 

The Ideal LED Grow Light Spectrum for Plants

RGB LED lighting for an indoor farm

(RGB LED lighting for an indoor farm)

Some light spectrums encourage growth in plants. Generally, red light encourages flowering, stem elongation, and leaf growth. 

On the other hand, blue light promotes structural and vegetative growth.

 Moreover, different crops respond uniquely to spectrums on different occasions during their growth cycle.

 Here, let’s look at the important LED grow light spectrum for plants. 

Ultraviolet Light Spectrum 

The UV light falls outside the PAR range having wavelengths ranging from 100 to 400nm.

 It is crucial for plant growth as it contributes to their color, taste, and nutritional value.

 Moreover, using a controlled amount reduces the effects of pests and fungi on plants. 

Blue Light Spectrum

The blue light spectrum falls between 400 and 500nm. It’s important for plant growth as it increases plant quality in leafy crops such as vegetables.

 Specifically, it opens up stomata allowing plants to take in more carbon dioxide for photosynthesis. 

Additionally, blue light encourages seedling and young plant growth by promoting healthy root structure. 

Green Light Spectrum

Green wavelengths fall between 500 and 600nm and are often disregarded due to the inability to absorb chlorophyll. 

In reality, plants absorb as much as 95 percent of green light due to their ability to penetrate canopies. 

Red Light Spectrum

Red wavelengths are the most significant light spectrum as they promote photosynthesis. 

They fall between 600 and 700nm, and plants absorb them highly for general vegetative growth.

 Additionally, pairing red and blue lights counteract each other to prevent overstretching in plants.

Far-red Light Spectrum

Between 700 and 800nm is the far-red light that promotes shade avoidance in plants.

 In other words, it makes the plant grow toward light, promoting the stretching of branches and stems. 

Furthermore, far-red light encourages flowering and fruit yield in some plant species. 

The Science Behind Adjustable Spectrum LED Grow Lights

Phytolamps illuminate potted plants

(Phytolamps illuminate potted plants)

Adjustable spectrum LED grow lights promote plant growth by utilizing plant photobiology. In other words, they allow a grower to control the wavelengths that reach a plant.

 Also, their science involves providing a plant with the exact light wavelength they need to optimize that specific growth stage.

Furthermore, they manipulate plant phytochromes to promote growth. Phytochrome red absorbs red light and converts it into phytochrome far-red to promote stem elongation. 

On the other hand, phytochrome far-red absorbs far-red wavelengths and converts back to phytochrome red to prevent flowering at an early growth stage.

When a plant reaches a vegetative stage, you can adjust the light to provide more blue and red light to promote leafy growth. 

As the plant grows towards the flowering stage, a farmer increases the ratio of red light to promote fruiting.

Advantages of Adjustable Spectrum LED Grow Lights

A young biologist inspecting a plant

(A young biologist inspecting a plant)

Adjustable spectrum LED grow lights allow growers to customize the wavelengths according to the needs of the plants.

 In effect, farmers control the growth patterns such as flowering and fruiting. 

Second, they are durable, making their longevity outweigh the high initial cost. 

Third, adjustable spectrum lights are cheaper as they require fewer replacements than other lighting technologies.

 Moreover, they eliminate the need for multiple light fixtures for each plant growth stage. 

Fourth, adjustable spectrum lights allow growers to customize light recipes to achieve specific characteristics. 

For instance, varying ratios and intensity of light influence aroma, flavor, and color in some plant species. 

Considerations of Adjustable Spectrum LED Grow Lights

A man in deep thought

(A man in deep thought)

Plant knowledge: Using an adjustable light spectrum requires one to know a plant cycle and its light requirements. 

Failure to do so results in poor yields or abnormal plant growth patterns. 

Cost: Adjustable LED grow lights have a higher initial cost than non-adjustable spectrum LED lights. 

On the brighter side, their customization benefits outweigh the high upfront budget. 

Complexity: Adjustable LED grow lights have complex control systems that may be tough for non-technical growers to grasp. 

Therefore, you may need some experience to use the lights well and get the desired results.


Are full-spectrum LED lights good for growing plants?

Full-spectrum LED lights are advantageous for growing plants since they emit the full range of the electromagnetic spectrum. 

Their light closely mimics the sunlight ranging from ultraviolet light, across visible lights, to infrared light. 

Consequently, plants can receive all the light they need for different stages, from seeding to fruiting. 

A good thing about full-spectrum light is that it leaves the task to the plant to select the wavelengths it needs. 

Therefore, a plant can take in a blend of wavelengths that promote optimal vegetative growth and flowering. 

Moreover, a farmer doesn’t have to spend time adjusting the wavelengths to suit a growth stage.

How do I determine the right spectrum for my plants using adjustable LED grow lights?

You can determine the right spectrum for your plant by studying the plant growth cycle. With adjustable LED grow lights, you can begin with a broad spectrum before narrowing it down to the specific one.

In that way, you’ll have time to research the requirements of your plant species and vary the spectrum accordingly. 

Furthermore, you need to understand the growth stage needs of the plant. Plants need varying levels of red, blue, UV, and far-red lights from seeding to fruiting.

Can adjustable spectrum LED grow lights replace traditional grow lights?

Adjustable spectrum LED grow lights are replacing traditional grow lights for several reasons. First, they are energy efficient, converting most of the wattage to light energy.

Conversely, traditional light sources convert 20 percent of energy to light energy. 

In other words, a 20-watt LED light can produce more lumens than a traditional grow light of the same capacity. Second, LED grow lights to produce little heat, making heat management easier for farmers. 

On the other hand, traditional grow lights generate a lot of heat, and you will have to install fans to safeguard your plants from heat stress.

Third, adjustable spectrum LED grow lights last between 50,000 and 100,000 hours under good maintenance. 

Conversely, traditional grow lights last between 1,000 and 10,000 hours. As a farmer, it’s better to use adjustable spectrum LED grow lights.

The initial cost will be high, but you will reap benefits from the longer-lasting adjustable spectrum LED grow light.  


Growers are enthusiastic about the adjustable LED grow lights as it gives them control over their plants.

In that way, they can influence the yield from specific plants in the garden.

For instance, marijuana growers tailor red and far-red light ratios to promote certain flavors. 

Additionally, you will save in the long run as you won’t need different light technologies for each growth stage.