When growing cannabis, growers must adjust the color and intensity of their lights based on the plant’s current growth stage. This replicates the way the plant would naturally receive light in nature.
For example, during the vegetative stage, cultivators prefer blue spectrum lights. They do this because plants need this particular type of light to develop longer stems and bigger leaves.
Blue Light
When it comes to cannabis growth and yield, the impact of different types of light is vital. As growers, we want to maximize our yields while maintaining high quality plants. This means we must pay close attention to the types of lighting we use – and how it affects a plant’s growth, flowering, taste, smell etc.
One of the most important light spectrums for cannabis is blue. This is because it promotes compactness and bushiness, which are key factors for growing taller, thinner plants that can support flower formations.
It’s also an important part of the photosynthesis process. Chlorophyll pigments absorb blue light efficiently, which enables them to produce more nutrients for the plants to use.
The ideal light spectrum for your plants depends on your goals – how much you want to accomplish with each cycle of growth, what type of plant you’re growing and more. For example, some growers increase blue light exposure to their plants at the end of the flowering cycle to stimulate terpene production.
This can result in a more intense aroma and higher levels of THC and other cannabinoid concentrations, according to Hopper. In addition to this, increasing blue light exposure during the flowering stage can alter a plant’s taste and potency, which is a huge benefit for cannabis growers who are trying to create unique strains.
The best grow lights are full spectrum, meaning they provide all the colors a plant needs to thrive and achieve its maximum potential. They are also convenient and affordable, allowing you to switch between varying light colors without changing a bulb.
Red Light
Cannabis plants are highly sensitive to different wavelengths of light throughout their growth cycle, and growers should know how to best use grow lights for each stage. For example, growers should adjust light intensity, color, and frequency for the germination, vegetative, flowering, fruit, and stem elongation stages of their plants’ growth.
In addition, light spectra affect plant morphology, growth traits, and key secondary metabolite profiles. These effects strongly depend on the specific light spectra and light intensity used, as well as other environmental and crop-specific factors.
Red light (660 nm) is important for cannabis growth and yield, as it stimulates germination and promotes flowering. It also helps suppress fungus such as downy mildew and powdery mildew, and inhibits the growth of pest insects.
Blue light (430 nm) is also used to encourage vegetative growth. The bright direct light reflects off of the plant’s surface and helps it spread out as much as possible to increase leaf mass and photosynthesis.
Unlike blue, red lights can influence photomorphogenesis, making cannabis leaves bigger. However, growers should be careful about using too much red light, as it can cause plants to stretch and elongate, which isn’t desirable.
Studies show that the ratio of red versus far-red is important for photomorphogenesis in cannabis, as the higher the red:far red ratio, the taller the plant will be. This is why growers are often tempted to use a high R:FR ratio to boost yield, but this can be problematic if the plant is not receiving enough red in relation to the amount of far-red it receives.
The six experimental LED light treatments evaluated were blue (430 nm), red (630 nm), rose (430 + 630 nm, ratio B:R 1:10), purple (430 + 630 nm, B:R ratio 2:1), and amber (595 nm). Results showed that the use of all six light spectra impacted growth traits and key secondary metabolite profiles under the same light intensity.
Yellow Light
The impact of different types of light on cannabis growth and yield can be confusing. There is so much information out there from growers and experts online that it can be hard to decipher what is true or false.
The first stage of growth is the vegetative stage, where it’s primarily recommended to provide blue light in order for plants to grow strong and healthy leaves. Many indoor growers use metal halide bulbs, compact fluorescent lamps (CFL’s) or T5/T8 lighting fixtures with a blue band to achieve this.
However, the amount of blue light a plant needs during this time varies greatly depending on the cultivar and the desired yield. Ultimately, it’s up to the grower to figure out what is best for their specific grow room and goals.
Another important factor that can impact flowering is the red to far-red ratio of the light spectrum. The R:FR ratio is a key determinant of the plant’s morphology, flowering, and even germination.
For example, when a cultivar has a high R:FR ratio (like Skunk), they can have taller stems and petioles compared to a low R:FR ratio (like OG Kush). Some growers believe that giving far-red light at the end of the day will help short-day plants bloom faster, but this isn’t supported by science.
Despite the lack of scientific proof, some growers claim that giving far-red light to cannabis at the end of the day increases the bud size and terpene content. While this may be true in some cases, it’s not the most effective approach for maximizing bud production and THC levels. It also depends on the genetics of the cultivar. It’s therefore important to use grow lights that emit a wide spectrum of light and vary the amount of blue, red, and far-red light according to the specific plant requirements.
Orange Light
Orange light is a very powerful mood enhancing color that has been linked to many positive health benefits including increasing energy levels, reducing stress and improving sleep. It is also known to improve cognitive function and increase alertness.
Research has shown that orange light can make you more alert by stimulating the prefrontal cortex, which is believed to be responsible for high cognitive functions and overall alertness. A team of researchers studied brain activity in volunteers undergoing fMRI scanning while they were exposed to blue and orange lights.
It seems that the orange wavelength wakes up the brain’s melanopsin pigment, which acts like a switch, telling your brain to be more or less alert. When it was retested after being exposed to a green light, people who were initially exposed to orange had more brain activity in areas related to alertness and cognition than those who were first exposed to blue.
This research shows that orange light can boost alertness and can even have an impact on your circadian rhythm. It also helps improve memory by increasing brain activity in the prefrontal cortex.
The key here is to choose the right light for your needs. You need to consider how often you want to grow weed, what type of lighting you have available and the amount of money that you can spend on your electricity bill.
Ideally, you need a light that provides a good balance of the different wavelengths. This will ensure that the plants are getting enough of the essential photons in the correct wavelengths.
There are a few different types of cannabis grow lights to choose from, but they typically use a combination of metal halide (MH) and high-pressure sodium (HPS) lamps. MH lights are used early in the growth cycle to promote compact, bushy plants while HPS lights are used during the flowering and fruiting phases of the plant’s lifecycle.
White Light
White light is a term used by some holistic healers and spiritualists to describe a pure energy that can be called upon for purification and transformation. It is said to be a space in the universe that houses positive energies, like angels, saints, and ascended masters.
White light can also be used to clean the aura of a person or an object. This is done by directing negative or dirty energies toward the light for purification and transformation (similar to what you might do when you wash your clothes at a dry cleaner).
Cannabis plants grow in the green spectrum during the vegetative stage of growth, which is where they make lots of big leaves and short stems. They are also able to adapt to different levels of blue and red light, which they are able to use to help them grow.
The impact of different types of light on cannabis growth and yield is important to consider for growers because it can affect how fast the plant grows, what kind of bud they will produce, and the amount of THC that the plant can contain. This information can help growers decide what type of lighting to use and when to switch to another light type based on the type of growth they want to achieve.
Indoor cannabis production is a highly energy-intensive process because of the high capital and maintenance costs of lights (Mills, 2012; Evergreen Economics, 2016). Consequently, crop lighting is one of the most important input costs for growers, which can limit their ability to maximize yield and quality within a specific budget.
