How Does the Grow Light Spectrum Influence Cannabis Growth?

Growing cannabis indoors can be a fun and potentially lucrative hobby. However, it is essential to comprehend the cannabis plant's life cycle in order to cultivate a healthy plant. Given that cannabis is a photosensitive plant, the schedule of your plant's exposure to light is crucial to its growth.

That is why purchasing high-quality,full-spectrum grow lights is crucial for cultivating a healthy, high-yield cannabis plant. 


Full Spectrum


However, it’s not enough. 

Because you will not be able to take full benefit of your grow light spectrum if you do not understand how different wavelengths of light affect your cannabis based on their growth cycle stage. Therefore, knowing how to adjust the light intensity, color, and frequency for each of its growth stages is crucial.


How Do Different Colors of Light Affect the Growth of Cannabis?

Blue Light Wavelengths

The synthesis of chlorophyll, which helps plants absorb light, is significantly influenced by blue light. This light is best to use during vegetative growth, as it helps the plant produce more leaves and grow taller. It also encourages stem cells to produce longer stems. However, blue light can also be detrimental to your plant. 

The germination stage is when the plant starts to grow and develop roots, stems, leaves and flowers. When you use blue light during the germination stage, it can inhibit the growth of your plant. This is because blue light interferes with the phytochrome, which is the plant's natural response to light. When the phytochrome is disrupted by blue light, it doesn't respond correctly and the seed is unable to germinate.


Green Light Wavelengths

Green light has been demonstrated to have a positive effect on the growth of cannabis as it does not interrupt the plant's night cycle by mimicking moonlight. However, green light contributes minimally to the plant's growth and development. 

As compared to the absorption of blue or red light by chlorophyll, green wavelengths have been deemed to be less significant. Although not critical, green light still regulates plant architecture and photosynthesis.


Red Light Wavelengths

Red light, specifically 660nm, is the wavelength of light that most cannabis plants use to create their own energy. This means that the more red light a plant is exposed to, the faster it will grow. Red light is vital for the cannabis germination and flowering stages. Adding red light encourages flowering and budding. When a cannabis plant is ready to bloom or bud, many growers increase the intensity of the red lights they were using.

However, much red light might lead your plants to stretch and grow tall, resulting in lesser yields and wobbly, elongated plants. To avoid this, grow indoors with a consistent light cycle of 16 hours of light and 8 hours of darkness per day.


UV Wavelengths

Did you know that UV is the reason why you need to wear your sunscreen when you’re outdoors? That's because overexposure to UV light can cause skin damage and lead to skin cancer.

So why would you want your plants to be exposed to UV wavelengths? Well,  UV light increases the terpene production in the cannabis plants. This is a good thing because terpenes are the compounds that give cannabis its flavor and fragrance.

UV Wavelengths

By exposing your plants to UV light, you’ll be able to increase their production of terpenes. In higher concentrations, ultraviolet light can also harm plants. But with a  small tolerable amount of UV light or UV rays can improve the aroma, flavor, potency, and growth of cannabis plants.


What is the Best Light Range for Cannabis Growth?

Cannabis growth cycle consists of four stages: germination, seedling, vegetative, and flowering. Each phase of the cannabis growth cycle is vital to the success of your crop as a whole. Also, different spectrum colors play distinct roles in the progression and maturation of cannabis plants. Consequently, it is essential to consider the spectrum of light colors, as their effects on plant growth vary based on environmental factors.

Therefore, knowing what your cannabis requires at each stage will help you to choose the optimal grow light spectrum for each stage.

The blue light spectrum between 400 and 500 nm is optimal for cannabis plants throughout their vegetative phase. At 460 nm, plants receive the signal to produce resilient, broad leaves. During flowering, red light with a wavelength between 620 and 740 nm can be used to maximize yield.

Take note that the development rate of plants and how quickly photosynthesis happens can be influenced by the growing lights and their color temperature, with a sweet spot at 660 nm. 


What are the Best Full Spectrum Grow Lights?

Brands come with a reputation and a promise to deliver. That’s why you should always do your research before making any major purchase. When it comes to full spectrum grow lights, there are many brands and models to choose from. Some are better than others, but there are some that stand out above all others.

But with so many options on the market, how do you know which brand is the best?

Let’s take a look at some of the most popular brands of full spectrum grow lights and see how they stack up against one another.


Horticulture Lighting Group


Horticulture Lighting Group

Horticulture Lighting Group (HLG) is a lighting manufacturer that was founded in 2016. The merger of Johnson Grow Lights and Northern Grow Lights led to the creation of their first high density modular light engine, LED Quantum Boards, which has been a game-changer in the horticultural lighting industry. Their dedication to research and development ensures that they provide high quality products to their customers.


Grower's Choice

Grower's Choice

A complete product line, Grower’s Choice has all your lighting needs covered, from fixtures to LEDs and controllers. Thanks to the experience of the people behind the brand, Grower’s Choice understands the needs of gardeners, especially those with special requirements.

Whether you are a hobbyist or a commercial grower, the Grower’s Choice product line can help your garden bloom


Spider Farmer

Spider Farmer

Spider Farmer is a lighting company that designs and manufactures high-quality, competitively-priced LED grow lights. Since its humble beginnings in 2015, Spider Farmer has sought ways to bring its products closer to consumers, no matter where they are in the world.

The company takes pride in its exceptional customer support and listens to what the market wants, so it can deliver the products people want.


The Green Sunshine Co

The Green Sunshine Co

The Green Sunshine Co. is a company that specializes in LED grow lights for all your gardening needs. These powerful lights are compact and easy-to-use, yet they provide your plants with the full spectrum of light they need to reach their full potential and grow at a faster rate than ever before. With its wideband spectrum, your plants can get all the nutrients they need to produce high-quality crops that taste amazing.

Whether you're new to gardening or an old pro, The Green Sunshine Co.'s products will help you get the most out of your plants and make growing fun again!


Optic LED


Optic LED


When you want to grow your own plants, but don't want to spend a fortune on expensive lighting systems, Optic LED Grow Lights is what you need. They've designed their product line of grow lights to be affordable without ever sacrificing quality. They've studied the top brands of grow lights, including their weaknesses, and they responded with a series of affordable grow lights without scrimping on quality.




NextLight LED Grow Lights


NextLight is a pioneer of full-spectrum LED technology. NextLight design, develop, and manufacture products that are designed to meet the needs of commercial and home growers alike. NextLight's full spectrum LED grow lights provide the sun-like qualities plants love without the negatives of high energy requirements and high heat. And all NextLight products come with the best 5 year warranty in the industry, covering all components down to the diode.


Final Thoughts

It's clear that the grow light spectrum influences cannabis growth, but what isn't clear is how much of this influence is due to the actual spectrum of light and how much is due to the intensity of that light. However, the answer is that both matters.

The intensity of light can help you increase your yields, but only if you use it at the right time. If your cannabis plants receive too much light at any stage of their life cycle, they may grow tall and lanky or have a reduced yield. Indeed, it's critical to understand how cannabis plants use light and how this can impact their growth.