Understanding Spectrum LED Grow Lights

Understanding spectrum LED grows lights is important if you plant your crops indoors or in a greenhouse. 

Generally, outdoor plants grow with the help of sunlight by picking the wavelengths that promote their growth at that given stage. 

Now, for indoor plants, the fact that they can’t access sunlight means that you have to provide light artificially.

 And that is where the spectrum LED grow lights come in.

In today’s article, we are delving into all you need to know concerning LED grow lights and more.  

What Is Spectrum LED Grow Lights

Growing medical cannabis sativa indoors

(Growing medical cannabis sativa indoors)

Spectrum LED grows lights are artificial systems that provide specific electromagnetic wavelengths for optimal plant growth and photosynthesis.

 Generally, you can adjust the wavelengths corresponding with a plant’s growth stage from seeding to flowering. 

For example, to promote photosynthesis, shine a light with an electromagnetic wavelength between 400 to 700 nanometers. 

Additionally, plants can detect a wider range of wavelengths beyond what the human eye can perceive.

 Our eyes can only detect lights between 380 and 740 nanometers, or what we refer to as visible light. 

Spectrum LED grows lights are popular for indoor and greenhouse lighting applications to supplement or replace natural sunlight.

How Spectrum LED Grow Lights Influence Plant Growth

Spectrum LED grow lights substitute sunlight for indoor and greenhouse plants.

For example, they provide a balance of red and blue lights, which drive photosynthesis. 

Without the wavelengths, your plants would die due to the inability to produce chlorophyll and synthesize carbohydrates.   

Secondly, plants need certain spectra to absorb chlorophyll and promote morphogenesis

Without them, your plant may develop unproductive stem elongation and branching, among other undesirable patterns. 

Thirdly, a high percentage of red light triggers flowering and fruiting in most plant species. 

Without it, plants won’t produce flowering hormones like phytochromes leading to lesser yields. 

Different Spectrums for Different Growth Stages

An indoor hydroponic farm

(An indoor hydroponic farm)

Specific light spectrums cause unique growth attributes in plants.

Here, let’s look at maximizing plant growth using diverse spectrums. 

  • Red light spectrum:  Red light promotes photosynthesis, stem elongation, flowering, and leaf growth. Remember to balance it with blue light to offset overstretching and excessive leaf growth. 
  • Blue light spectrum: On the other hand, blue light promotes vegetative growth, especially in leafy crops. Additionally, it encourages strong root and stem growth in seedlings.
  • Greenlight spectrum: Important for photosynthesis, although at a less degree than the red light spectrum. 
  • UV light spectrum: Using small amounts of UV on your plants limits the impact of pests and fungi. However, overexposure to UV lights can harm your plants.
  • Far-red light spectrum: Promotes shade avoidance reaction and flowering in some plants.

The Benefits of Using Spectrum LED Grow Lights in Indoor Cultivation

You can place spectrum LED grow lights closer to the plants

(You can place spectrum LED grow lights closer to the plants)

Spectrum LED grow lights are important to indoor cultivation for several reasons.

 If you’ve ever grown plants indoors, you know they are weak and yield fewer fruits or leaves.

Here, let’s look at why you need spectrum grow lights. 

Increased Growth and Yield

Spectrum LED grow lights increase plant growth and yield as they shine light, that’s important for photosynthesis.

 As a result, plants grow to have strong roots, stems, and branches to support the fruits. 

Greater Control of Plant Growth

You can control the intensity and duration of spectrum LED grow lights on your plants.

In this way, you’ll enhance plant growth for better yields.

 For instance, you can shine specific wavelengths for a given period before turning it off. 

For example, you can use a red wavelength on your plants for three hours if you know that’s the duration for optimal flowering. 

Energy Efficient

The good thing about LED lights is that they are almost 90 percent more efficient than traditional light sources like fluorescent lamps.

 Interestingly, fluorescent bulbs convert about 90 percent of the power supply to heat energy while only 10 percent to light. 

Conversely, LEDs convert more than 90 percent of the power supply to light energy. 

Accordingly, go with LED lights if you need an efficient spectrum system that consumes less electricity.  

Better Heat Management

LEDs produce less heat than fluorescent and high-intensity discharge (HID) lights. 

Therefore, they lower the risk of plant damage due to heat stress.

 Furthermore, it allows you to place the lights closer to the plant.  

Long Lifespans

LED lights are durable and can last for more than 50,000 hours. 

In contrast, fluorescent and incandescent bulbs last between 1,000 and 10,000 hours of service. 

Thus, LEDs are the better option to save on spectrum light replacement and operational costs. 

What the Future Holds

An indoor vertical farm

(An indoor vertical farm)

We are seeing greater advancements in agricultural technology as the world shifts towards improving efficiency and efficacy. 

First, we see LED technology advancements that increase photon efficiency and spectral distribution. 

Consequently, you’ll save more while optimizing plant growth.

 Second, we continually understand plant biology, especially how they respond to light. 

Soon, we’ll be able to tailor wavelengths that improve specific plants. 

Third, scientists are working to integrate plant growth with smart technologies. 

The technologies shall do real-time monitoring of plants to aid growers in creating specific lighting profiles for different plants.


Do I use different spectrum lights for each plant?

You should use different spectrum lights on each plant species since they have unique growth rates.

Remember, specific wavelengths promote optimal plant growth at each stage.  

For example, plants in the vegetative stage need blue light, while those in the flowering stage need more red light. 

Therefore, if you plant various plants in your greenhouse, plant them separately to maximize their spectrum light input.  

What is the best LED spectrum for grow light?

Generally, there’s no best LED spectrum for growing light since plants need unique wavelengths during growth. 

Furthermore, the type of grow light you’ll use depends on the plant species you are cultivating and its growth stage. 

Typically, a plant in the vegetative state needs a lot of blue light for a stronger foundation and leafy growth. 

On the other hand, a plant at the flowering stage needs a higher percentage of red light.

Red light stimulates optimal flowering and fruiting in plants. 

We recommend using full spectrum lights if it is tough to time the LED spectrum lights according to your plant’s growth stage. 

The lights mimic natural sunlight, combining red, blue, and white light. 

Therefore, they support the plant throughout its growth stage.

How do I know if my LED is full-spectrum?

Some lights that plants need are beyond what the human eye can perceive. 

As such, the only way to tell if your LED is a full-spectrum light source is to look at its specifications. 

Moreover, look for the spectrum chart that comes with the light.

If it has a balanced distribution of red, blue, and white light, chances are that it is a full-spectrum LED. 

Another way to know is by checking to see if its color temperature resembles natural sunlight.

It should be around 5000K to 6500K. 

In other words, it has a lot of white light with lesser combinations of blue and red light wavelengths.

And, if you’re still unsure, your last option is to contact the manufacturer for more information on the specific LED spectrum light. 


Planting plants indoors without light hinders their growth, yield, and flavor.

 You may have seen indoor plants with thin elongated stems and sometimes yellowish leaves. 

The reason for such undesirable growth characteristics is that they lack access to certain light wavelengths.

 And, general light sources in our homes don’t provide the wavelengths. 

Consequently, it would be best if you bought lights that, by design, produce red, blue, white, or a combination of the three for better yields.