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Cannabis Facility Build GuideCannaCribs Video Breakdown

Under Canopy Lighting: Boost Yield, Bud Quality & ROI in Commercial Cannabis [Video Breakdown]

By February 19, 2026May 15th, 2026No Comments
CannaCribs Video Breakdown

Under Canopy Lighting: Boost Yield, Bud Quality & ROI in Commercial Cannabis

[Video Breakdown]

Under-canopy LED bars placed below the plant canopy can turn lower "popcorn" buds into denser, higher-value flower — without expanding your footprint. In this CannaCribs episode, Nate breaks down the real-world benefits, the data behind the results, how to vet fixtures using third-party DLC testing, common implementation mistakes, and which products currently stand out on efficiency.

Key Takeaways
  • Under-canopy lighting is increasingly a competitive necessity — not a trend. Commercial growers who skip it are likely leaving yield on the table.
  • The biggest upside is converting lower and middle bud sites into denser, A-grade flower, reducing larf/popcorn and increasing sellable biomass.
  • Benefits go beyond yield: reduced lollipopping labor, improved plant structure, and potentially improved microclimate below the canopy.
  • Reported results include ~20%+ yield lifts, 27% improvement in bud size, and significant A-grade flower increases across multiple case studies.
  • Don't shop on marketing claims alone — use the DLC Hort QPL to compare reported vs tested photometric performance before buying.
  • Execution determines results: start 14–21 days into flower, validate HVAC capacity, place bars 8–12 inches below canopy pointing upward, and match spectrum to your overhead fixtures.
Close-up of dense, high-quality cannabis flower — the result of optimized lighting including under-canopy supplemental bars
This is what under-canopy lighting is chasing — dense, A-grade flower throughout the plant, not just at the top cola sites that overhead lighting reaches easily.
Why Under-Canopy Is "The Hot Topic" 0:10–1:30

Commercial cultivation economics reward higher output from the same footprint. Under-canopy aims to "unlock yield that's already there" by delivering usable light into shaded bud sites below the canopy — turning more of the plant into harvestable, high-quality flower without expanding square footage. CannaCribs Consulting now recommends under-canopy lighting for all new facility installations where budget allows.

The 6 Core Benefits 1:32–3:49
  • More yield, same footprint: Illuminating lower bud sites unlocks additional harvestable biomass — higher grams per sq ft without expanding the facility
  • Better bud quality: Light reaching lower branches converts popcorn buds into dense, A-grade nugs throughout the plant
  • Full-plant photosynthesis: More uniform light distribution reduces stretch and produces sturdier, more desirable plant morphology
  • Labor savings: Reduced or eliminated lollipopping/pruning because lower sites develop into viable flower
  • Airflow and microclimate friendly: Slim, passively cooled bars don't block airflow — but measure temps/RH before and after install and adjust fans as needed
  • Potential pest/disease reduction: Fewer dark, humid zones below the canopy make conditions less hospitable for some pests and pathogens
What the Data Says 3:51–4:52
  • TSR Grow study: ~20% yield increase and 27% enhancement in bud size
  • California Lightworks Mega Drive at Harborside greenhouse: 29.84% increase in total dried trimmed flower and 11% rise in A-grade flowers
  • Thrive Agritech research: substantial A-grade flower increase, improved cannabinoid and terpene profiles, 5% THC increase
Choosing the Right Fixture: Specs That Matter 4:54–6:08

Three core spec buckets to evaluate when comparing under-canopy fixtures:

  • Wattage: Total power draw that impacts heat load and operating cost
  • Spectrum: The spectral makeup (blue/green/red/far-red) and how it pairs with your top lighting
  • Efficiency (µmol/J): A "miles-per-gallon" metric for how effectively a light converts electricity into usable photons. A fixture at 3 µmol/J is 50% more efficient than one at 2 µmol/J. Target ≥2.5 µmol/J; top models reach 3.0+.
Indoor cannabis cultivation room showing ceiling fan arrays — airflow management is critical when adding under-canopy lighting bars
Adding under-canopy bars increases heat load and can affect humidity below the canopy. Validate airflow with fans adjusted before and after install — stagnant air under a full canopy is a common source of heat stress when under-canopy lighting is poorly executed.
How to Spot Marketing Hype: Use the DLC Hort QPL 6:08–10:08

The DesignLights Consortium (DLC) maintains Qualified Products Lists including a horticultural category (Hort QPL). Create a free account at designlights.org, click "Find Products" → "Hort QPL," then search any LED fixture.

What to look for on each listing:

  • Reported vs tested photometric performance: If a manufacturer reports 2.7 µmol/J but testing shows 2.5, they are overstating efficiency. You want tested performance to meet or exceed reported claims.
  • Spectrum breakdown: Review blue/green/red/far-red band distribution and confirm it fits your lighting strategy and top-light pairing
  • Third-party vetting evidence: DLC listing signals both reliability screening and potential eligibility for utility rebate programs

Nate's guidance: be very cautious about buying a light that is not listed in the DLC — it means there is no third-party reporting confirming its actual efficiency or performance claims.

Things to Avoid When Implementing 10:09–12:23
  • Running too early: Don't use in veg or early flower — wasted energy. The ideal time is 14–21 days into flower, after the initial stretch
  • Underestimating HVAC + humidity load: More power = more heat; full canopy increases transpiration rates. Ensure adequate cooling AND dehumidification capacity before install
  • Bad placement: Bars should point upward, positioned 8–12 inches below the canopy leaves. Use adjustable stands. Poor angle dramatically reduces effectiveness
  • Spectrum mismatch: Match spectrum to your overhead lights where possible to avoid conflicting signals to plant photoreceptors. Full-spectrum tops → full-spectrum under-canopy. Red-enhanced tops → red-dominant under-canopy can work
  • Ignoring airflow validation: Monitor temperature and RH at the bottom of the canopy after install and adjust fans accordingly
Products and Next Steps 12:25–14:26

There's no one-size-fits-all fixture — the best light depends on your operation, room design, and budget. Notable options as of mid-2025:

  • Illuminar: Most powerful 4-foot under-canopy bar at 160W (most are 120W)
  • California Light Works Mega Drive: Patented daisy-chain system — hundreds of fixtures, 120–480V flexibility
  • FloraFlex: Highest efficiency at 3.3 µmol/J (at time of recording)

In some regions and programs, utility rebates have covered 100% of the cost of under-canopy lighting installations. Always check rebate eligibility through your utility provider and use DLC-listed fixtures to qualify. If you're growing cannabis commercially and trying to be as competitive as possible, under-canopy lighting is no longer optional — it's part of your competitive edge.

Work With Experts on Your Cannabis Lighting Strategy

The CannaCribs consulting team evaluates lighting strategies as part of full facility design — integrating fixture selection, PPFD modeling, HVACD load calculations, and energy efficiency planning into a single, defensible approach. Whether you're designing a new facility or optimizing an existing one, they can help you get under-canopy (and your entire lighting strategy) implemented correctly from day one.

CannaCribs cannabis facility consultants working on-site with a commercial cultivation team on lighting and facility optimization
CannaCribs Consulting validates under-canopy lighting strategies on-site — checking fixture placement, PPFD uniformity, HVAC load impact, and airflow before and after installation.
Full Video Transcript

Complete timestamped transcript — Under Canopy Lighting: Boost Yield, Bud Quality & ROI.

[00:00:10]

Hey everyone, Nate from CannaCribs. So today we're talking about under canopy lighting because it is one of the hottest topics in cannabis cultivation at this moment in time. And if you're not using under canopy lighting in your cannabis grow and you're growing as a business, you're probably kind of falling behind. So, let's chat about that a little bit.

[00:00:31]

You know, if you're not using under canopy lighting, you could be losing yield to larger buds and your competition could be pulling more weight and more A-grade colas. You know, referring to those larger, more dense, potent buds that normally are only at the top of your plant, but you can be getting those in the middle and bottom of your plant. So, they're doing that with the same amount of square footage.

[00:00:52]

Under canopy really isn't the latest trend. It's becoming a necessity for a lot of growers who want to stay competitive and boost their yields per square foot and maximize the value of every plant they have in their facility. When building out new facilities or optimizing existing facilities, our CannaCribs consulting team is now recommending under canopy for all building installations. As long as you have the budget for it, it makes a ton of sense on the front end.

[00:01:32] Benefits

Let's talk about the core benefits of under canopy lighting first. There are six of them. When we talk about under canopy lighting, we're really talking about unlocking yield that's already there in your plant. It's just kind of hiding in the shadows.

[00:01:48]

One: you can get more yield from your garden with the same footprint. By illuminating the lower bud sites that are otherwise remaining shaded, the under canopy lighting unlocks basically this additional harvestable biomass. It supports higher grams per square foot without expanding the facility footprint.

[00:02:12]

Two: boost in bud quality. A lot of your plant—what comes off of it—are these popcorn-like buds. With light reaching the lower branches, you're going to get more dense A-grade nugs.

[00:02:25]

Three: full plant photosynthesis. Cannabis plants tend to stretch towards the light source, which can lead to elongated stems and less desirable bud structure. Providing light from below makes the plant grow more uniformly and reduces the stretch — resulting in a sturdier, more desirable plant morphology.

[00:02:43]

Four: labor saving. Cannabis growers usually trim or prune plants below the canopy — "lollipopping." With under canopy lighting, you can eliminate or vastly reduce lollipopping because you're going to get good bud formation down there.

[00:03:10]

Five: air flow and microclimate friendly. Under canopy lights are slim and passively cooled bars. They won't really block air flow or create heat pockets as long as you have proper air flow in your room. Make sure to measure the air flow, temperature, and humidity within your canopy before and after installing your lights.

[00:03:32]

Number six: decreasing pests and disease. Under canopy lighting actually deters some pests from hanging out in the shadowy areas of your plant. It also reduces the relative humidity in that area below the plant, which makes the area less hospitable to some pathogens and pests.

[00:03:51] Data

A study highlighted by TSR Grow revealed a 20% increase in yield and a 27% enhancement in bud size when under canopy was utilized. A performance test of California Lightworks Mega Drive reported a 29.84% increase in total dried trimmed flower and 11% rise in A-grade flowers at the Harborside greenhouse. Research by Thrive Agritech indicated a substantial increase in A-grade flowers, improved cannabinoid and terpene profiles, and a 5% increase in THC levels across the crop.

[00:04:54] Choosing the Right Fixture

Under canopy lights are measured by wattage, spectrum, and efficiency measured in micromoles per joule (µmol/J). If a light is rated at 2 µmol/J and another at 3 µmol/J, the 3 µmol/J light is 50% more efficient at converting power into plant-growing light. It's like miles per gallon in your car, but for grow lights and photosynthesis.

[00:06:08] Using the DLC

There's a third-party organization called DLC — DesignLights Consortium. It provides third-party testing and certification for LED grow lights. Make an account at their website, click "Find Products" → "Hort QPL." Then search any LED grow light submitted to DLC. Compare reported vs tested photometric performance. The reported was 2.4 µmol/J on one example — but tested was 2.5. That means they actually report less than they test. What you look for is the opposite problem: a manufacturer claiming 2.7 but testing at 2.5, meaning they're overstating efficiency.

[00:10:09] Things to Avoid

Number one: turning on the lights too early — don't use in veg. Ideal time: 14–21 days into flower, after the initial stretch. Two: heat buildup — more power = more heat; ensure adequate HVAC and dehumidification; monitor temps at the canopy bottom. Three: placement — point lights upward, 8–12 inches below canopy; use stands. Four: spectrum mismatch — try to match spectrum to your top lights to avoid confusing plant photoreceptors.

[00:12:25] Products

Illuminar: most powerful 4-foot bar at 160W. California Light Works Mega Drive: daisy-chainable, 120–480V. FloraFlex: most efficient at 3.3 µmol/J as of May 2025. In some places, utility rebates paid for under canopy lighting 100%. Under canopy lighting is no longer optional for commercial cannabis growers. Grow smarter, light deeper, and harvest better.

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