Exploring the Effects of Far Red Light on Cannabis Growth

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The world of cannabis cultivation has been punctuated by advancements in horticultural technology, stepping up the game of growers by leaps and bounds! In the vanguard of this innovation are LED Grow Lights, especially those dancing on wavelengths unknown to many – Far Red Light. Buckle up as we delve deep into the discovery of how this mysterious part of the light spectrum is revolutionizing cannabis growth, profoundly impacting both quality and quantity in ways previously unimaginable. With groundbreaking research and unexpected benefits lining our exploration, this journey into the realm of Far Red Light promises a glimpse into the future of cannabis cultivation.

Far-red light, particularly when used in combination with other wavelengths, has been found to promote stem elongation, increase plant height, encourage flowering, and boost yields in cannabis plants. This can be achieved through the use of specialized grow lights that emit a spectrum rich in far-red light or by timing exposure to far-red light during specific stages of the plant’s growth cycle. However, it is important to note that these effects may vary based on the strain of cannabis and environmental factors, so experimentation and careful observation may be necessary to achieve optimal results.


Understanding the Far-Red Light Effect

Far-red light, or far-red radiation, has been found to have significant effects on plant growth, including cannabis. But what exactly is the far-red light effect and how does it impact the growth of plants? Let’s delve into the details.

Far-red light refers to wavelengths in the range of 700-750nm, which are longer than those of red light. It plays a crucial role in horticulture as it has been observed to enhance cell expansion in plants when combined with white LEDs. This combination creates a synergistic effect that positively influences photosynthesis. Far-red light is also naturally present in many sources of light, such as sunlight, high-pressure sodium (HPS) lights, and ceramic metal halide (CMH) lights.

To illustrate the effect of far-red light on cannabis growth, consider this scenario: when cultivators expose their cannabis plants to higher percentages of far-red light during the flowering stage using specialized lighting systems such as from Green Sunshine Company, it can lead to greater internodal distance. This means that the spaces between each set of leaves or branches become more pronounced, resulting in taller plants. Additionally, a phenomenon known as the Emerson effect comes into play during this stage. The combination of red and far-red light triggers a response that promotes flowering and can potentially increase yields.

Far-red light is not only limited to height enhancement but also impacts other aspects of plant growth. Research conducted by Bruce Bugbee highlights its potential in increasing leaf size and stem length. While these effects have been predominantly studied in cannabis cultivation, there is growing interest in exploring the benefits of far-red light in other crops as well.

Now that we have a foundation for understanding the far-red light effect on plant growth, let’s explore an important factor that influences how plants perceive different wavelengths of light – phytochromes.

  • Research from The Green Sunshine Company suggests that nearly 60% of a plant’s overall dry weight can be positively affected by far-red light.
  • Studies have shown that using far-red light can increase the leaf size and stem length in cannabis plants by up to 30%-40%.
  • According to several scientific studies, including those conducted by Bruce Bugbee, incorporating far-red light into the daily light schedule can boost yields in cannabis plants by approximately 10%-20%.
  • Far-red light, with wavelengths in the range of 700-750nm, has been observed to positively influence plant growth and enhance photosynthesis in combination with white LEDs. Exposure to higher percentages of far-red light during the flowering stage in cannabis cultivation can lead to taller plants with greater internodal distance and potentially increase yields, as the Emerson effect is triggered by the combination of red and far-red light. While its effects have been predominantly studied in cannabis cultivation, there is growing interest in exploring the benefits of far-red light in other crops as well. Phytochromes are an important factor that influences how plants perceive different wavelengths of light.

Role of Phytochromes in Perception of Light

Phytochromes are light-absorbing pigments that play a crucial role in how plants perceive the quality of light. These special proteins can exist in two forms: the red-absorbing form (PR) and the far-red-absorbing form (PFR). The interconversion between these two forms allows plants to detect changes in light conditions.

Phytochromes are responsible for mediating various physiological processes in plants, including seed germination, stem elongation, leaf expansion, and flowering. When activated by light, phytochromes undergo a molecular change, triggering a cascade of events within the plant’s cellular machinery.

For example, when a plant is exposed to red light, the phytochromes predominantly convert into the active PFR form. This signals to the plant that it is receiving sufficient light for photosynthesis and growth. On the other hand, exposure to far-red light leads to the conversion of phytochromes into the inactive PR form, signaling shade or the end of daylight hours.

Consider this analogy: think of phytochromes as plant sensors that can detect different wavelengths of light. Like a switch that turns on or off depending on the color of light it senses, phytochromes help plants understand their environmental conditions and respond accordingly.

Understanding the role of phytochromes in perceiving and responding to light is crucial in harnessing the power of far-red light for optimized plant growth. By manipulating these pigments’ activation levels through targeted lighting strategies, cultivators can tailor their approaches to suit specific crop requirements.

Far-Red Effect’s Impact on Cannabis Growth

The far-red light spectrum, ranging from 700 to 800 nm, plays a significant role in cannabis growth and development. When exposed to far-red light, cannabis plants exhibit particular responses that have proven beneficial for cultivators. Let’s explore the impact of the far-red effect on cannabis growth and understand why it holds such importance.

One of the key effects of far-red light is its ability to promote faster and more vigorous growth. This response is known as the Emerson effect, named after American scientist Robert Emerson who discovered this phenomenon in photosynthesis. The presence of far-red light enhances the overall efficiency of photosynthesis, leading to increased biomass production in cannabis plants. As a result, growers can expect healthier and more robust plants with improved yields.

To provide an example, imagine two identical strains of cannabis being cultivated under similar conditions, with one exposed to supplemental far-red light and the other not. The plant receiving the additional far-red light would likely exhibit accelerated growth rates, taller stature, and larger leaves compared to its counterpart. This difference in growth can have a profound impact on overall crop productivity.

Another crucial aspect influenced by the far-red effect is the regulation of flowering response in cannabis plants. Far-red light is often used strategically during different stages of cultivation to manipulate photoperiods and stimulate flowering. When exposed to an extended duration of far-red light during the dark period, cannabis plants perceive this as a signal indicating autumn or late-stage growth conditions. Consequently, they initiate the flowering process earlier than they would under normal circumstances.

Furthermore, studies suggest that far-red light can also affect various morphological characteristics of cannabis buds, including size and density. By carefully manipulating the duration and intensity of far-red exposure during specific growth phases, cultivators can potentially enhance bud quality and increase cannabinoid content. This presents an exciting opportunity for growers aiming to optimize their output and produce higher quality cannabis.

Far-Red light also exhibits interesting properties related to cellular absorption. Generally speaking Far-Red light has a much higher penetration effect versus the other spectrum of visible light. This penetration power results in lower leaves growing larger to increase their photon capture ability. For our legacy growers who say HPS has a higher canopy penetration, they are partially right. Its not due to the intensity of the light, rather, the spectral output of the fixture. Greens and Yellows along with Far-Red have a much deeper penetration capability vs Red and Blue light.

Influence on Chlorophyll Production and Photosynthesis

Photosynthesis, the process by which plants convert light energy into chemical energy, is vital for the growth and development of cannabis. Far-red light plays a significant role in influencing photosynthetic processes and chlorophyll production in cannabis plants.

Chlorophyll, the pigment responsible for capturing light energy during photosynthesis, is essential for plant growth and vitality. The presence of far-red light affects both chlorophyll a and chlorophyll b production in cannabis plants. Research suggests that exposure to far-red light can increase the concentrations of these pigments, enhancing the efficiency of light absorption during photosynthesis.

Additionally, the influence of far-red light extends beyond just increased chlorophyll production. It also influences other aspects of photosynthetic activity, such as stomatal conductance and carbon assimilation. Stomata are small pores present on the surfaces of leaves that enable gas exchange between plants and their environment. Far-red light has been shown to regulate stomatal opening and closure, thereby impacting water loss through transpiration and CO2 uptake for photosynthesis.

Stomata Diagram Via Science Facts – Stomata

The ability of cannabis plants to efficiently capture and utilize light energy directly correlates with their overall productivity. By exposing plants to controlled levels of far-red light at specific stages of cultivation, growers can optimize photosynthetic efficiency and maximize biomass accumulation. This strategic use of far-red light can lead to healthier plants with increased vigor and improved yields.

Effects on Bud Quality and Color

When it comes to cannabis cultivation, the quality and color of the buds are of paramount importance. Far-red light has been found to have a significant impact on both these aspects, offering potential benefits for cultivators.

Far-red light not only enhances bud color but also influences their development. It promotes the accumulation of secondary metabolites such as anthocyanins, flavonoids, and other compounds responsible for producing unique flavors and aromas in cannabis plants. These compounds contribute to the overall quality and desirability of the buds, making them more appealing to both consumers and connoisseurs.

Moreover, far-red light has been shown to increase trichome production on cannabis buds. Trichomes are tiny resin glands that contain cannabinoids like THC and CBD, as well as terpenes. They play a vital role in providing therapeutic effects and creating distinctive flavors. By enhancing trichome production through the use of far-red light, cultivators can potentially achieve higher levels of potency and flavor complexity in their cannabis products.

The main mode of action for Far-Red light to positively affect cannabis plants is that this particular spectrum of light increases the absorption efficiency of other spectrums of light. By increasing the amount of chlorophyll A and B, the cannabis plant can more efficiently produce more THC, CBD, Terpenes, and other secondary metabolites, thus increasing overall crop quality and flower weight.

Now that we’ve explored the effects of far-red light on bud quality and color, let’s dive into its impact on yield output.

Impact on Yield Output

Cannabis cultivators constantly strive to optimize their yield output, seeking ways to increase productivity without compromising quality. Incorporating far-red light into cultivation strategies has shown promise in achieving this delicate balance.

Studies have found that far-red light can promote increased stem elongation and internode spacing in cannabis plants during the flowering stage. This means that plants exposed to far-red light will likely grow taller, allowing for more bud sites to develop. The increased internodal distance also helps prevent crowding and promotes better airflow, reducing the risk of mold or mildew issues.

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Furthermore, the Emerson effect, which refers to the positive influence of far-red light on photosynthesis during the flowering stage, can contribute to enhanced yields. Far-red light has been shown to supplement the benefits provided by other lighting sources, such as white LEDs or high-pressure sodium (HPS) lights. This synergy between different spectrums of light can maximize the efficiency of photosynthetic processes, leading to overall improved biomass production and larger yields.

For instance, a cannabis cultivator utilizing a combination of far-red light and other appropriate lighting sources throughout their cultivation cycle might witness denser flower formation and higher overall harvest weights compared to using traditional lighting methods alone.

While far-red light holds promise in boosting yield output, it’s important to note that other environmental factors such as temperature, humidity, nutrient availability, and genetics also play crucial roles. Cultivators should take a holistic approach and consider how these factors interact with the effects of far-red light to achieve optimal results in terms of both quantity and quality of crop.

Implementing Far-Red Light in Cannabis Cultivation

Implementing the use of far-red light in cannabis cultivation has gained significant attention and intrigue among growers. The effects of manipulating the light spectrum during different stages of plant growth can have substantial impacts on crop productivity, quality, and overall yield. Far-red light, which falls between 700 and 800nm on the light spectrum, offers unique properties that influence various aspects of cannabis growth and development.

One of the key benefits of implementing far-red light is its ability to regulate photomorphogenesis, which refers to how plants respond to light signals. Far-red light can reduce the flowering period of cannabis by up to 15% and enable quicker crop turnover. It does not directly drive photosynthesis like other wavelengths but influences plant height, internode length, and other morphogenic formations.

To visualize this effect, imagine a cannabis plant that is exposed to a higher ratio of far-red light in the spectrum. This will likely result in longer internodes between the leaves along the stem, making the plant appear taller and less bushy. On the other hand, a lower ratio of far-red light would promote shorter internodes, resulting in a more compact plant structure with increased branching.

Additionally, manipulating the ratio of red (660nm) to far-red (approximately 730nm) light can impact certain characteristics of cannabis plants. The R/FR (red to far-red) ratio affects plant morphology, including stem node distance, plant height, axillary bud differentiation, chlorophyll content, stomatal index, and leaf area. By utilizing various ratios of these wavelengths throughout different growth stages, growers can shape their crops according to their desired outcomes.


For example, using far-red light at the end of the day for a short duration can make cannabis plants bloom in the dark or induce “night interruption.” This technique can potentially increase yields by 20% per year. However, it’s important to note that the effect of far-red on cannabis yield is strain-dependent, as different varieties start flowering at different times of darkness.

Now that we understand the potential benefits and effects of implementing far-red light in cannabis cultivation, let’s explore the suitable types of light sources that can provide this specific spectrum.

Suitable Types of Light Sources

When it comes to providing far-red light to cannabis plants, there are several options of light sources available for growers to choose from. Each type has its own advantages and considerations, depending on factors such as cost, energy efficiency, and implementation ease.

  1. LED Grow Lights: LED technology has revolutionized indoor cultivation by offering precise control over light spectra. LED grow lights with far-red spectrum options are readily available for testing and implementation. These lights can be customized to provide specific ratios of red to far-red wavelengths, allowing growers to fine-tune their desired outcomes.
  2. Supplemental Lighting Solutions: Some growers opt for supplemental lighting solutions alongside their primary light source. By incorporating separate fixtures or bulbs emitting specific far-red wavelengths, growers can tailor the overall lighting environment in their grow space to promote desired plant responses.
  3. HID (High-Intensity Discharge) Lamps: HID lamps, such as high-pressure sodium (HPS) or metal halide (MH) lamps, have long been used in horticulture and can provide a broad spectrum of light including far-red wavelengths. While they may not offer the same level of control as LED lights, they can still be effective in certain cultivation setups.

It’s worth mentioning that regardless of the light source chosen, careful consideration should be given to factors such as intensity, duration, and distance from plants. Experimentation and monitoring the response of cannabis plants under different lighting conditions will help growers refine their approach and achieve optimal results.

Ideal Light Exposure Periods

When it comes to cannabis cultivation, understanding the ideal light exposure periods is crucial for optimizing growth and yield. Cannabis plants require a balance of light and darkness to go through different growth stages effectively. Let’s explore the key light exposure periods in the lifecycle of cannabis plants.

During the vegetative stage, a longer light period is generally preferred. Providing 18 to 24 hours of light per day helps promote rapid growth and development of the plant’s foliage. This extended exposure allows for increased photosynthesis, which results in stronger stems, lush leaves, and overall plant vigor.

As cannabis plants transition into the flowering stage, adjusting the light exposure becomes essential. Typically, providing 12 hours of uninterrupted darkness and 12 hours of light signals the plants to start producing flowers. This photoperiod mimics the natural changes in daylight during autumn, triggering proper flower development. It’s important to maintain consistency in these light-dark cycles to avoid interrupting or delaying the flowering process.

It’s worth noting that cannabis cultivators may experiment with manipulating light exposure periods to achieve specific outcomes. For instance, some growers employ techniques like “24-0” (24 hours of continuous light) during early vegetative growth to accelerate initial development before transitioning to standard lighting schedules. Others may use techniques like “12-1” (12 hours of darkness followed by one hour of low-intensity light) towards the later stages of flowering to extend budding time and potentially enhance resin production.

Imagine a grower named Alex who noticed that their cannabis plants were growing too tall during the vegetative stage due to a longer light exposure period. To rectify this issue, Alex decided to adjust the cycle by reducing the daily light period from 24 hours to 18 hours. The shorter exposure allowed for more balanced growth and prevented excessive elongation.

Optimizing light exposure periods can contribute significantly to achieving desired cannabis cultivation outcomes. Additionally, it’s essential to consider the spectrum of light provided to maximize plant productivity and cannabinoid production. Far-red light has emerged as a fascinating area of research in this regard.

Research and Future Applications of Far-Red Light in Cannabis Cultivation

In recent years, researchers and cannabis cultivators have been exploring the effects of far-red light on cannabis growth and development. Traditionally, photosynthetically active radiation (PAR) consisting of wavelengths between 400 to 700 nanometers (nm) has been considered crucial for plant growth. However, recent discoveries at Utah State University regarding far-red photons and photosynthesis have led to a new definition of PAR known as ePAR or extended PAR.

Studies indicate that exposure to far-red light can enhance multiple aspects of cannabis cultivation. For example, it has shown the potential to increase plant biomass, stem elongation, flower yield, and even the production of secondary metabolites such as cannabinoids and terpenes. Researchers are also investigating the specific effects of far-red light on gene expression within cannabis plants, aiming to improve the predictability and consistency of crop yields.

With continuous advancements in technology and research exploration, the future applications of far-red light in cannabis cultivation appear promising.

The integration of far-red lighting systems into indoor cannabis facilities is an area that holds immense potential. By understanding the specific responses elicited by different wavelengths, growers can fine-tune their lighting setups to influence plant growth patterns effectively. Moreover, combining far-red light with other techniques like crop steering (guiding growth through tailored lighting, humidity, nutrients, etc.) opens up new avenues for optimizing yield quality and quantity.

Consider far-red light as a key ingredient in a recipe for successful cannabis cultivation – its specific addition can enhance the flavors and aromas while boosting overall yields.

As research on far-red light continues to expand, growers can anticipate more comprehensive guidelines and techniques that harness its potential benefits. The insights gained from ongoing studies will enable cultivators to refine their cultivation strategies and achieve higher crop quality, consistency, and potentially even the development of specific medicinal traits.