Dynamic LED Grow Lighting: The Future of Commercial Horticulture?

In the rapidly evolving landscape of controlled environment agriculture (CEA), multi-channel LED lighting is emerging as one of the leading technological innovations. These systems enable precise, real-time adjustment of light intensity and, in some configurations, the light spectrum itself, in response to the plants’ needs, natural light levels and even demand on the electrical grid. The potential benefits are real, but so are the drawbacks. This article covers both sides so you can decide whether multi-channel lighting makes sense for your commercial growing operation.

Dynamic and Dimmable Are Not the Same Thing

These two terms are often used interchangeably in marketing copy, and the difference matters when you are comparing quotes.

Dimmable means you can adjust the intensity of the light. Most modern single-channel and all multi-channel LED fixtures are dimmable, using 0-10V dimming, the Horti Lighting Protocol (HLP), or DALI dimming protocols. Luminaires can be controlled using either wired or wireless configurations.

Dynamic and tunable both mean you can manipulate the spectrum, changing the ratio of red, blue, white and far-red light reaching the crop. This requires independently driven channels of different colours, which in practice means a four-channel fixture.

A two-channel fixture with a far-red channel gives you a degree of spectral control, letting you switch a second wavelength on or off, but it is not fully tunable in the way a four-channel fixture is. When a supplier calls a product “tunable”, ask how many independently controlled colour channels it has and what each one emits. If you want the underlying vocabulary first, our guide to photosynthetic photon flux and efficacy metrics covers the measurements these conversations depend on.

Customizable Light Recipes

Dynamic or tunable LEDs enable precise control over the light spectrum, allowing growers to tailor lighting conditions to the specific requirements of various plant cultivars and developmental stages. On-demand spectral customization can be used to enhance photosynthesis, influence plant morphology, and potentially increase yields.

This could be valuable for growers in a highly competitive or specialty crop market, where the ability to dial in the optimal spectral recipe for a specific cultivar can produce crop quality or productivity improvements that distinguish them from the competition.

In other cases, growers may wish to futureproof their grow environment to allow for different crop types they may choose to grow later, based on the shifting profitability of certain crops or other unforeseen impacts such as crop virus outbreaks.

Although growers typically picture a four-channel fixture when they hear “dynamic spectrum”, there are also two- and three-channel products available. These offer a broad, efficient spectrum on the main channel for the majority of the lighting schedule, with one or two additional channels that allow limited applications of other wavelengths as and when they are needed.

For example, the ParFX Ultra 2-Channel fixture runs a recipe of 90% red, 5% white and 5% blue on the main channel, with a second far-red channel.

Specific applications of far-red light have been shown to be beneficial, though the mechanism differs by crop and the effect depends on dose and timing:

• Chrysanthemum. In Wageningen University & Research trials, extending the day by 30 minutes with 20 µmol/m²/s of far-red light at the end of the day produced measurable stem elongation in all four varieties within two weeks, and longer flowering shoots in the three truss varieties (Wageningen University & Research, 2022).
• Sweet pepper. In a 24-hour lighting trial where part of the daily far-red was re-timed from day to night rather than added on top, far-red at night increased internode length, which opens up canopy architecture and prevents fruit stacking. Far-red preferentially drives stem and internode extension, while blue light at night preferentially supports leaf expansion, and the authors note the two responses may run on different mechanisms (Lanoue, Little & Hao, 2022).

Both results share a pattern worth noting. The benefit comes from controlled stem or internode extension at a specific point in the cycle, not from a general increase in growth, and in both cases the effect depended on applying far-red on a defined schedule rather than continuously.

Conversely, blue light* can act as a growth regulator that suppresses stem extension, which is useful when height requirements are a factor or when plants need to be more compact. Adding a modest proportion of blue to red light has also been shown to increase chlorophyll and carotenoid content and antioxidant capacity across lettuce, spinach, kale, basil and sweet pepper, though the optimal blue fraction differed by species (Naznin et al., 2019).

Determining the optimal light spectrum for each crop and growth stage requires extensive knowledge and experimentation. The interactions between light spectra and plant responses are complex, and missteps can lead to sub-optimal growth or reduced yield. Our article on how plants respond to light quality goes deeper into those relationships.

So while the idea of adjusting and experimenting with your grow lighting is genuinely exciting, and a valuable tool for some, the reality is that commercial growers depend on consistency and predictability. Growers subject to supply contracts with grocery chains or garden centres are focused on delivering consistent quality and yield against those contracts, so they generally prefer to eliminate as many variables as possible. Because changes in light intensity and spectrum affect not only other inputs like nutrient uptake and VPD but also plant morphology, growers are advised to set up a trial area first, to see how their crops perform under various spectral recipes rather than risk compromising one or more harvest cycles across the entire crop.

For growers who do not want to spend time working out the optimal light spectrum, and the necessary adjustments to other inputs, for each specific crop and cultivar, a fixed spectrum optimized to accommodate multiple crop types and growth stages may make more sense. Our comparison of full spectrum versus red and blue LEDs covers that trade-off in detail.

Maintaining Optimal Light Intensity

Growers have long relied on the “1% light rule”, the assumption that a 1% increase or decrease in light produces a corresponding 1% change in yield. When Marcelis et al. tested that assumption across a range of greenhouse crops, they found the real response is usually smaller. For most crops a 1% light increment produced a 0.5 to 1% increase in harvestable product, and for fruit vegetables such as cucumber, tomato and sweet pepper the range was 0.7 to 1%. The relative effect is greater at lower light levels, and under higher CO₂ concentrations and temperatures, which is why it is larger in winter than in summer (Marcelis et al., 2006).

Researchers including Dr. Erik Runkle and Dr. Bruce Bugbee have made the case that as light intensity rises, spectral effects tend to diminish, so light quantity has the more consistent effect on crop growth. Bugbee is explicit that spectrum still matters, only less. Runkle’s example is that long-day plants flower best under a spectrum including red and far-red, but once the daily light integral exceeds roughly 12 to 15 mol/m²/day, red light alone is just as effective. Neither researcher argues that spectrum stops mattering, only that it matters less than total light delivered.

What growers often do not realize is that on a tunable fixture, the amount of light produced changes with the spectral recipe you dial in. Using P.L. Light Systems’ 4-Channel ParFX Ultra Max as an example:

Between the highest and lowest of those recipes there is a difference of roughly 8% in photon flux. Applying the measured response for fruit vegetables, that translates to somewhere around 5 to 8% in yield. Efficacy moves in the same direction, from 4.26 down to 3.93 µmol/J, so the same fixture is also converting electricity to photons slightly less efficiently as red content is diminished.

Spectral tuning therefore needs to be balanced against maintaining adequate light intensity. As a grower, you need to weigh the economic benefit of the potential morphological improvements, whether that is taste, colour or nutritional value, against the potential decrease in yield. Our article on light intensity and high yields covers the intensity side of that equation.

Energy Efficiency and Power Management

LED luminaires are known for their high energy efficiency compared to traditional lighting systems such as high-pressure sodium (HPS). They convert electricity to light more efficiently and are dimmable, reducing energy consumption and operational costs over time.

In addition to the energy savings offered by all high-quality LED systems, multi-channel fixtures allow real-time adjustment of light intensity in response to natural light levels or demand on the electrical grid, delivering greater control over energy use.

One caveat worth stating plainly. This is a power-management benefit, not an efficacy guarantee. As the table above shows, photon efficacy still varies with the spectral recipe you select.

Because multi-channel fixtures draw across several circuits, the electrical supply matters too. Our guide to voltage requirements for grow lights covers what to confirm before installation.

Control Protocols

Some lighting manufacturers have developed their own lighting management systems, based on proprietary communications protocols, for real-time adjustment of light intensity and spectrum as well as power management. P.L. Light Systems’ MeshIQ-enabled LED luminaires instead leverage the Horti Lighting Protocol (HLP) of existing climate control systems such as Priva, Argus or Hoogendoorn.

For the grower, the advantage of controlling lighting through an existing environmental control system, rather than a separate lighting-only management system, is that lighting can be integrated into an overall greenhouse power management strategy that includes heating equipment, screen controls and more. The environmental control system can also manage a facility-wide energy strategy that integrates with utility demand response programs, where equipment use is scheduled to reduce load on the electrical grid during peak demand periods.

Through HLP, the MeshIQ wireless control system offers plug-and-play integration with the Horti Lighting Protocol module of existing climate control systems, without proprietary control protocols or recurring subscription fees. As a grower, you own and control your lighting equipment.

The short overview below shows the MeshIQ module mounted on the fixture.

Cost of Multi-Channel Versus Single-Channel Systems

The upfront cost of a multi-channel tunable LED system is typically, and often significantly, higher than that of a fixed-spectrum LED system. Aside from the higher price of the fixtures themselves, there may be additional costs for compatible control systems or software, including potential upgrades to activate the HLP module. Multi-channel systems are also more technologically complex than fixed-spectrum lighting, which may require additional training for staff.

The ability to fine-tune light spectra lets growers influence not only growth rates but crop qualities such as the concentration of desirable compounds, flavour, colour and shelf life. While customers may be willing to pay more for these enhancements, and the incremental revenue could offset the lighting system cost over time, the initial capital outlay may be a barrier for some operations. Our breakdown of how to determine ROI on a lighting investment sets out the calculation.

Who Tunable Lighting Actually Suits

If you sell into a specialty or high-value market where colour, flavour or shelf-life commands a premium, spectral control may be a lever worth having. If you are delivering consistent volume against supply contracts, it adds variables you will spend the season managing rather than focusing on production yield.

The honest test is whether spectral control changes what you can charge for your product. If you are not able to charge a premium for your end product, a fixed spectrum solution optimized across your crops costs less to purchase, less to run, and less to think about.

Either way, set up a trial area before committing across the operation. The interactions between spectrum, nutrient uptake and VPD are specific enough to your facility that no specification sheet will predict them accurately for you.

Frequently Asked Questions

What Is Dynamic LED Grow Lighting?

Dynamic LED grow lighting, also called tunable lighting, refers to fixtures whose light spectrum can be adjusted, changing the ratio of red, blue, white and far-red light reaching the crop. Growers use it to match the spectrum to crop stage, to natural light levels, or to demand on the electrical grid. Adjusting the spectrum is different from dimming, which changes intensity only.

What Is the Difference Between Dynamic and Dimmable LED Lighting?

Dimmable refers to adjustable intensity. Dynamic, or tunable, refers to an adjustable spectrum, meaning the ratio of red, blue, white and far-red light can be changed. Tuning the spectrum requires independently driven colour channels, which in practice means a four-channel fixture. A fixture can be dimmable without being tunable.

Does Changing the Spectrum Influence Light Output?

Yes. On a tunable fixture the total photon flux changes with the recipe selected, because each colour channel has a different output and efficiency. On the 4-Channel ParFX Ultra Max, output ranges from 5,180 µmol/s on a 95% red and 5% blue recipe down to 4,783 µmol/s on a recipe with 10% far-red, a difference of roughly 8%. Photon efficacy varies across the same range.

Is Tunable LED Lighting Worth the Cost for Commercial Growers?

It depends on whether spectral control earns you money. For growers in specialty or high-value crop markets, where a specific spectral recipe improves colour, flavour or shelf life enough to command a premium, the added capital cost can be justified. For growers delivering consistent volume against supply contracts, a fixed spectrum optimized across multiple crops and growth stages is often the better fit, because it removes variables rather than adding them.

Can Multi-Channel LED Fixtures Work With My Existing Climate Computer?

They can if the fixture supports the Horti Lighting Protocol (HLP) used by climate control systems such as Priva, Argus and Hoogendoorn. Fixtures that rely on a manufacturer’s proprietary protocol generally require a separate lighting-only control system, which sits outside your facility-wide energy strategy. Some of these proprietary systems also require a paid subscription over and above the cost of the luminaires, which carries its own risk in letting a third party control your future. Confirm protocol support before purchase.

If you would like a spectrum and intensity plan modelled against your own growing area and crop, our team can put together a light plan.

*Due to the high energy of these wavelengths, working under high-intensity light, especially blue, in greenhouses or indoor grows may pose a risk to eye health. All P.L. Light Systems LED products are Certified to UL 8800, the safety standard for horticultural lighting equipment, published in August 2019 for equipment intended for installation in both the United States and Canada.

Anyone spending a prolonged period in a CEA facility with LED lighting should follow the optical safety instructions indicated on the product labels, and it may be a good idea to wear protective eyewear engineered for horticultural environments.