As a principal scientist at Fluence, I’ve spent years studying how lighting impacts plant growth, particularly in cannabis cultivation. One of the most common questions I get from growers is about intercanopy and subcanopy lighting—two strategies that promise to optimize yields and improve bud quality. However, there’s a lot of confusion surrounding these techniques. In this article I’ll break down what these lighting methods really mean, the common misconceptions, and when they might (or might not) be the right solution for your grow operation.
Intercanopy vs. Subcanopy Lighting: What’s the Difference?
The definitions are straightforward: intercanopy lighting (sometimes called intracanopy lighting) refers to placing light sources within the canopy itself—amongst the branches and leaves. Subcanopy lighting (or under-canopy lighting) involves placing lights below the canopy, either on the benches, pots, or floor, so that light shines upward onto the lower parts of the plant. Both methods aim to improve light penetration and ensure that lower bud sites receive enough photons to contribute meaningfully to yield and quality. But are they always the game-changer that some claim them to be?
Dispelling the Myths: Does More Light Always Mean More Yield?
A big misconception I often hear is that adding intercanopy or subcanopy lighting will automatically increase cannabis yields by huge margins—sometimes as high as 20% or more. While it’s true that additional light increases yield, the context matters. Many studies that show big yield jumps with intercanopy lighting are simply comparing a grow using standard top lighting versus one where additional lights were added within the canopy. Of course, if you add more total light to a crop, yield will likely increase! But here’s the reality: if you’re already using a well-optimized lighting setup with enough photons reaching the plant, simply redistributing light within the canopy may not provide the dramatic gains some expect. The key isn’t just adding light—it’s strategically distributing the light you already have to make sure it’s being used efficiently.
How Canopy Structure Determines the Best Lighting Approach
A major factor in deciding between intercanopy and subcanopy lighting is plant morphology. If you’re growing in a high-density setup where plants are tightly packed together, intercanopy lights might not penetrate effectively because they’ll be surrounded by dense foliage. In contrast, subcanopy lighting may be more beneficial in this scenario, as it can illuminate the entire underside of the canopy, helping lower leaves contribute to photosynthesis. On the other hand, if your plants are more widely spaced with significant gaps in the canopy, intercanopy lighting might be a more efficient way to distribute photons directly to bud sites. Every grow operation is unique, and the best approach depends on how your plants are arranged and how light naturally interacts with them.
Why Subcanopy Lighting Might Be the Better Bet for Most North American Growers
Based on our research at Fluence, most North American growers using standard setups—like four-foot-wide tables with rows of plants—tend to benefit more from subcanopy lighting than from intercanopy lighting. In controlled studies, we found that using subcanopy lighting led to an average yield increase of 7.1% across multiple cannabis cultivars compared to intercanopy lighting. While that’s not the massive 20% increase that some marketing claims promise, it’s still a significant and consistent boost in efficiency and profitability.
The Practical Challenges of Intercanopy and Subcanopy Lighting
One often-overlooked factor is the practical execution of these lighting strategies. Intercanopy lights, for example, require physical placement among the branches, which can make plant maintenance, movement, and even harvesting more difficult. Growers who frequently adjust plant positioning may find intercanopy lights to be a logistical headache. Subcanopy lighting, while easier to install and maintain, still comes with its own challenges. You need to manage cabling properly, keep fixtures clean, and ensure that placement does not interfere with irrigation or airflow. No matter which approach you choose, integrating secondary lighting requires thoughtful planning and consideration of your daily cultivation practices.
Avoiding Light-Induced Stress: The Role of Spectrum
Another critical factor when deploying intercanopy or subcanopy lighting is spectrum selection. Cannabis is highly responsive to different wavelengths of light, and too much red-light exposure can cause photo-bleaching in certain cultivars. t Fluence, our research suggests that a balanced, broad-spectrum light source is the safest and most effective choice for intercanopy lighting. Our VYNE 2.0 product for intercanopy lighting is BP6, which is an efficient light while still minimizing the risk of bleaching and providing the right balance of photons to drive photosynthesis effectively.
The Economic Case for Intercanopy and Subcanopy Lighting
From an ROI perspective, growers should consider more than just potential yield increases. The real financial benefit of intercanopy or subcanopy lighting often comes from improved bud uniformity. When lower bud sites receive sufficient light, you get fewer C-grade buds and more A and B-grade product—directly impacting profitability. However, the economics of lighting depend on the market you’re in. In some regions, high-quality buds fetch significantly more revenue, making secondary lighting a clear investment. In others, where price differences between bud grades are minimal, the ROI may not be as compelling. That’s why we always encourage growers to run the numbers—our team at Fluence is happy to help assess whether intercanopy or subcanopy lighting makes financial sense for your specific operation.
Considering the Whole Environment: HVAC and Beyond
When you increase light intensity—whether from top lights, intercanopy, or subcanopy sources—you also increase transpiration. That means your HVAC and dehumidification systems need to be equipped to handle higher moisture loads. Failing to account for this can lead to higher humidity, increased disease pressure, and ultimately lower yields. That’s why we always approach lighting as part of a holistic environmental strategy, ensuring that all factors—light, temperature, humidity, and airflow—are working in balance.
The Future of Intercanopy and Subcanopy Lighting
Looking ahead, I believe that research will continue refining the best practices for secondary lighting in cannabis cultivation. Specifically, I expect we’ll develop more precise guidelines to help growers determine when intercanopy or subcanopy lighting makes sense based on canopy density and plant architecture. Additionally, spectrum optimization will likely play a big role in the future. We’re already exploring ways to fine-tune subcanopy spectra to further enhance yield and bud quality. If successful, these advancements could fundamentally change how secondary lighting is deployed and dramatically improve efficiency for cannabis growers worldwide.
Final Thoughts: Is Secondary Lighting Right for Your Grow?
Ultimately, the decision to use intercanopy or subcanopy lighting depends on your specific setup, goals, and economic considerations. While subcanopy lighting appears to be the better fit for most North American growers, there’s no one-size-fits-all answer. The best way to determine if these strategies will benefit your operation is through careful planning, data-driven analysis, and a deep understanding of your crop’s needs. If you’re considering integrating secondary lighting into your grow, reach out to the Fluence team. We’re here to help you navigate the science, economics, and practicalities to ensure you get the best possible results. Let’s grow smarter together!
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