Under Canopy Lighting

For years, cannabis cultivation strategies have focused on lighting the top of the canopy as effectively as possible. As interest in under canopy lighting for cannabis cultivation continues to grow, more growers are rethinking how light is distributed throughout the plant.

Growers pushed higher intensities from overhead fixtures, hoping enough light would penetrate through the plant to support lower bud sites.

But in reality, dense foliage often means much of the lower canopy remains shaded, producing smaller flowers or material destined for extraction.

Befor we start this topic, may we could see what is it

What is under canopy lighting?

Under canopy lighting is a purpose-built LED system installed beneath the cannabis canopy, delivering high-efficiency photons directly to shaded lower bud sites.

This stimulates photosynthesis in tissue typically underdeveloped due to light loss at the top of the canopy, maximizing the productive parts of the plants.

Top-lighting alone cannot fully penetrate dense cannabis canopies, leaving lower bud sites underdeveloped and turning potential yield into trim waste.

Under-canopy lighting is a key component of the plant supplemental lighting system, designed primarily to address the issue of insufficient light—common with traditional overhead lighting—during the later stages of plant growth.

As the plant canopy thickens, upper leaves and buds obstruct light, making it difficult for the lower and inner sections to receive adequate illumination.

By adding supplemental light sources beneath the canopy, under-canopy lighting enables precise illumination of shaded areas; this helps improve light distribution uniformity, allowing more leaves and flower buds to receive effective light, thereby enhancing the overall light energy utilization efficiency of the cultivation space.

Why Under Canopy Lighting important?

In fact, on many forums, a large number of individual growers have already begun experimenting with this technique:

Is it merely a marketing gimmick?

Do the performance improvements it offers actually hold true?

To better understand the effects of supplemental lighting beneath the canopy, growers conducted a comparative trial to evaluate differences in plant growth performance with and without supplemental lighting.

Yield without undercanopy light: 626g with 139g of larfy Bud. Flowering Time 80days.

Yield with Under canopy light: 1018g with 16g of larfy Bud. Flowering Time 69 days.

Increase A-grade buds from 37% to 50% while reducing trim waste from 35% to 26%

High Efficacy

Deliver photons where they’re needed most for exceptional energy efficiency and maximizing yields

Distributed Lighting Strategy

Redistribute photons without over-driving top-lights, supporting enhanced flowering and bud development

Flexible Applications

Works across single-tier grows, multi-tier vertical farms, and greenhouses for optimal plant growth

Benefits Of Under Canopy Lighting For Cannabis Cultivation

Increased Light Penetration

In a densely packed canopy, light penetration to lower and inner foliage can be limited, resulting in shaded areas with reduced photosynthetic activity.

Under canopy grow lights supplement traditional overhead lights by delivering focused light directly to the lower canopy, ensuring that all parts of the plant receive sufficient light for photosynthesis.

This Improved light penetration promotes uniform growth, reduces the risk of underdeveloped buds, and maximizes the overall yield potential of the crop.

 A professional grow room utilizing under-canopy lighting during the early flowering stage.

Enhanced Bud Development

Under canopy lighting stimulates flowering and resin production in lower and inner bud sites that may be shaded or receive less light from overhead grow lights.

By providing supplemental light to these areas, growers can increase the size, density, and potency of buds throughout the entire canopy, resulting in higher yields of premium-quality flowers.

Improved light distribution also reduces the occurrence of popcorn buds and enhances overall bud structure and cannabinoid content.

 The primary function of under-canopy lighting is to increase the grade and yield of the lower buds.

Optimized Canopy Coverage

Under canopy lighting helps fill in gaps and shadowed areas within the canopy, resulting in a more uniform and consistent light distribution across the entire grow space.

By evenly illuminating the canopy from top to bottom, growers can optimize light coverage and minimize light stress on plants, ensuring balanced growth and maximizing the efficiency of photosynthesis.

A professional cultivation facility utilizes both under-canopy lighting and top lighting to achieve comprehensive light coverage without waste.

Increased Nutrient Uptake and Metabolism

Adequate light exposure to lower and inner foliage promotes active photosynthesis and carbohydrate production, supporting healthy root development, nutrient uptake, and plant metabolism.

Under canopy lighting enhances nutrient distribution throughout the plant, facilitating efficient nutrient absorption and utilization, which is essential for robust growth, flowering, and resin production.

Small-scale under-canopy lighting can also be used in home growing setups to help your users increase their yields.

Minimized Plant Stress and Disease Risk

Under canopy lighting reduces the need for excessive defoliation or canopy manipulation to improve light penetration, minimizing stress on plants and reducing the risk of pest infestations and plant diseases.

Well-illuminated lower foliage promotes air circulation, reduces humidity levels, and creates an environment less favorable for mold and mildew growth, contributing to overall plant health and vitality.

Design Strategy for Under Canopy Grow Lights

Targeted Spectrum

One of the biggest advantages of LEDs is their ability to emit specific wavelengths of light that are most effective for photosynthesis.

In under-canopy applications, red and far-red wavelengths are particularly useful for stimulating light-deprived leaves and encouraging better flower development at the lower nodes.

By supplying the right spectrum directly where it's needed, growers can maximize energy use and improve overall plant productivity.

Low Heat Output

LEDs produce minimal radiant heat, which means they can be placed inches from the plant without risking leaf burn or heat stress.

This is a major advantage in tight spaces under the canopy, where temperature control is critical and ventilation may be limited.

Cooler operating temps also reduce the need for additional HVAC support, making LEDs a safer and more efficient solution.

Compact, Modular Design  

Many under-canopy LED units are small, lightweight, and modular, making them easy to mount vertically along trellis lines or horizontally beneath dense plant rows.

Their low profile allows growers to position lights exactly where supplemental illumination is needed without interfering with airflow, pruning, or irrigation systems.

This flexibility is especially valuable in vertical farms and high-density commercial grows.

Custom Light Mapping

Advanced LED systems can be integrated with smart controllers, timers, and environmental sensors to deliver precise light intensity and spectrum on a zone-by-zone basis.

This allows growers to fine-tune supplemental lighting based on plant height, canopy density, and growth stage, helping to optimize uniformity and reduce energy waste.

Automation also minimizes labor and ensures consistent results across multiple cycles.

Longevity and Consistency

High-quality LEDs deliver stable light output and spectrum over thousands of hours, with little to no degradation. This consistency is essential for under-canopy lighting, where access for maintenance is limited.

Unlike HID bulbs, which lose intensity over time, LEDs provide long-term reliability without frequent replacements—making them a cost-effective investment for year-round production.