Indoor growing has evolved significantly over the past decade. As cultivators strive for higher yields and better plant health, innovative lighting strategies have become increasingly important. One such strategy is the use of under canopy lighting—a method that involves placing grow lights beneath the plant canopy to illuminate foliage from the bottom up. Though it might sound unconventional, there is a strong scientific basis behind this technique, and it offers a range of benefits that traditional top lighting alone cannot provide.
Understanding the Plant Canopy and Light Distribution
In typical indoor grow setups, light is delivered from above to mimic the sun’s natural direction. While this approach is effective, it often leads to a common problem: the light doesn’t penetrate deep enough into the canopy. As plants grow denser, their upper leaves shade the lower sections, drastically reducing the amount of light that reaches the bottom. This results in poor development of lower leaves and bud sites. These underdeveloped areas not only reduce yield but can also become sites of disease due to poor airflow and low light exposure.
What Is Under Canopy Lighting?
Under canopy lighting involves the strategic placement of LED grow lights beneath the plant canopy. These lights are designed to emit specific light spectrums—often red, blue, or full-spectrum white—that support photosynthesis in shaded areas of the plant. Their primary goal is to supplement areas that receive little to no light from above, effectively increasing total light coverage throughout the plant structure.
What are the Benefits of Under Canopy Lights
Enhanced Photosynthesis from All Angles
One of the most significant benefits of under canopy lighting is the stimulation of photosynthesis in the lower leaves. These leaves, although often neglected in traditional lighting setups, still contain chlorophyll and are capable of converting light into energy. When properly illuminated, these lower leaves contribute to the plant’s overall energy production, supporting more vigorous growth.
Better Bud and Fruit Development
For crops like tomatoes or peppers, under canopy lighting can dramatically improve the development of lower bud sites and fruit clusters. By providing direct illumination from beneath, growers can promote more even growth throughout the plant. This results in fuller, denser buds or fruit. In short, more of the plant becomes productive, translating into higher yields and greater profitability.
Reduced Shadowing and Light Stress
A more balanced light distribution can also prevent the extremes of light saturation and deprivation. When only top lighting is used, upper leaves can become overexposed, leading to light stress and photoinhibition, while lower leaves are starved of light entirely. Under canopy lighting helps to mitigate this imbalance by distributing light more evenly. This minimizes stress responses and supports a stable growth environment.
Lower Risk of Mold and Disease
Dense canopies with limited airflow are ideal breeding grounds for mold, mildew, and other plant pathogens. When the lower sections of the plant are left in darkness and high humidity, these problems can escalate quickly. Under canopy lighting helps to dry out these areas by warming and illuminating the lower foliage, reducing moisture buildup. In doing so, it lowers the risk of fungal infections.
Improved Plant Structure and Efficiency
Consistent lighting from both above and below influences how a plant directs its energy and develops structurally. Plants receiving light from multiple angles often exhibit more symmetrical growth, with less stretching and fewer weak points. This can be especially useful in vertical farming or high-density grow environments where every inch of space counts.
Final Thoughts
The science behind under canopy lighting is rooted in a deeper understanding of how plants interact with light. By addressing the limitations of top-only illumination, growers can unlock new levels of performance and productivity. Whether you’re cultivating leafy greens or fruits, integrating under canopy lighting into your grow strategy can help you achieve fuller canopies, healthier plants, and higher yields.