Why UV and IR Matter in Full Spectrum LED Grow Light

 

 

Within the field of indoor farming, the term "full-spectrum grow light" is now somewhat common. But does "full spectrum" actually encompass all the wavelengths that count to plants? Although many LED grow lights span the visible spectrum (400–700 nm), really high-performance systems incorporate UV and IR wavelengths.

 

LED grow lights with UV and IR provide more than just support for photosynthesis. Plant health, flowering, defence, and the production of cannabinoids or terpenes depend critically on these sometimes disregarded bands. This post investigates why adding UV and IR to LED grow lights might revolutionize serious gardeners.

 

 

First, let us define UV and IR light so that we can better appreciate their function.

 

UV (ultraviolet) light: It is defined by wavelengths between 100 and 400 nm. UV-A (315–400nm) is most often used in horticulture. Though more strong and dangerous, UV-B (280–315 nm) can also be used in limited doses.

 

IR (Infrared) Light: Wavelengths above 700nm, particularly far-red light (730nm), which influences photoperiodism, blooming, and elongation, are IR (Infrared) light.

 

Most basic LED grow lights exclude these ranges to reduce complexity or cost. But UV-IR LED grow light technology is changing that for good reason.

 

 

Although UV radiation does not greatly affect photosynthesis, its biochemical effect on plants is excellent and goes beyond illumination.

 

1. Drives the synthesis of secondary metabolites.
Doses of UV-A and regulated UV-B can boost the synthesis of terpenes, flavonoids, and cannabinoids. Because the plant generates more defensive chemicals in cannabis growing, UV exposure is connected to higher THC levels.

 

2. Improves Disease and Pest Management Opposition
UV light sets off the plant's natural defence mechanisms, activating genes that enhance cell walls and resistance enzymes. This helps crops be less susceptible to fungus, mites, and powdery mildew.

 

3. Enhances Plant Morphology

UV-A light makes shorter internodal spacing possible, resulting in more compact, strong plants-a desired quality for high-density cultivation.

 

One of the most underappreciated advantages of UV grow lights is the inherent improvement in plant quality-not only yield but also potency, taste, and durability.

 

 

Although IR light is invisible, it profoundly affects plants' interpretation of their surroundings, particularly via the phytochrome system.

 

1. Far-Red Light and Induction of Flowers
Specifically at 730 nm, IR light triggers Phytochrome Far-Red (Pfr), therefore enabling the plant to move from vegetative to blooming stages. In photoperiod-sensitive crops such as cannabis, far-red serves as a "flowering trigger."

 

Including far-red in your LED grow lights with UV and IR guarantees better-controlled and faster bloom cycles, which translates into shorter grow durations and higher harvest frequencies.

 

2. Control of Stretching Avoidance and Shade
Red:far-red light ratios let plants sense surrounding competitors. Depending on the Timing, controlled IR supplementation can change plant height, either encouraging stretching or maintaining compactness.

 

3. Nighttime Signals and Control of the Sleep Cycle
Flashing a far-red light at the end of a light cycle can assist in signaling " nighttime " to the plant, useful in photoperiodic control and perhaps energy savings during shorter dark periods.

 

Far-red is about Timing, efficiency, and maximizing your crop cycle rather than photosynthesis.

 

 

Many supposed full-spectrum grow lights lack UV and IR, even if they have advantages. This explains:

 

1. Cost Consideration: UV and IR LEDs cost more and call for very exact drivers and protective circuits.

2. Heat and Safety Concerns: Both UV and IR can create greater heat and demand a careful heat dissipation design.

3. Complexity in Control: Adding these bands makes spectrum modification and intelligent dimming more necessary in control.

 

Because of this, growers seeking enhanced outcomes sometimes choose UV-IR LED grow light systems instead of conventional ones.

Selecting a UV-IR LED Grow Light.

 

 

Bringing UV and IR into your grow lighting system unlocks multiple benefits:

Benefit	UV Contribution	IR Contribution
Potency Increase	↑ THC, CBD, Terpenes	–
Flowering Acceleration	–	Triggers photoperiod response
Disease Resistance	↑ Cell wall strength	–
Canopy Penetration	Slight increase	↑ Leaf expansion
Biomass Yield	Moderate increase	Significant via faster cycles
Morphology Control	↑ Compact growth	Control stretching

 

 

Search for an LED grow light with UV and IR for:

1. Different UV/IR control channels allow you to turn them on or off separately.

2. Passive cooling design and aluminum house for stable heat dissipation.

3. Designed in balance, not too much UV/IR to cause plant stress.

4. Helps tailor the light to the plant stage using dimming and timing characteristics.

 

At this point, I have to talk about our 4-way dimming LED Grow Light, which is composed of a 4-channel spectrum of VEG/BLOOM/IR/UV. Users can dim independently and freely combine the spectrum to meet the growth needs of different plants. We can provide LED grow lights from 240W to 1200W with UV and IR. If you want your cannabis planting to have high yield and good quality, you can't go wrong by choosing this LED Grow Light.

 

 

 

Growth Stage	UV Light (365–395nm) – Usage & Effects	IR Light (730nm) – Usage & Effects
Seedling Stage	❌ Not recommended – plants are too sensitive	❌ Not recommended – may cause excessive stretch
Vegetative Stage	⚠️ Optional, low intensity • Enhances resistance • Use < 30 min/day	⚠️ Limited use • May promote internode spacing (not ideal)
Pre-Flowering Stage	✅ Begin low-dose use • Start stimulating secondary metabolite production	✅ Recommended • Triggers flowering • 1–2 hrs/day
Early Flowering	✅ Continue low to moderate intensity • Enhances resin & aroma	✅ Strongly recommended • Accelerates flower development
Mid Flowering	✅ Moderate use • Increases THC/CBD production	⚠️ Optional • May still support flower stretch
Late Flowering	✅ Peak use • Maximize potency and terpene expression • 1–2 hrs/day	❌ Not recommended – avoid stretch, focus on density
Ripening / Flush	⚠️ Reduce or stop use • Avoid stress close to harvest	❌ Stop use – prevents loose bud structure

 

Modern indoor growing requires more than just red and blue light. Growers can use UV-IR LED grow light solutions to release a deeper level of plant control, improving everything from root strength to bloom output.

 

Integrating LED grow lights with UV and IR helps you go beyond simple photosynthesis and towards a smarter, higher-yielding, and more resilient grow system-whether your plants are herbs, fruits, or valuable commodities like cannabis.

 

JT Grow Light is a 10+ manufacturer specializing in LED Grow lights. We focus on spectrum and product design to provide growers with efficient and economical full-spectrum LED grow lights. We have successfully helped customers in the United States, Thailand, Canada, Europe, and other countries to provide LED lighting solutions. Customers have shared their planting results after using our LED Grow Light. At the same time, we are also very grateful for the support and trust of our customers. If you are troubled about how to choose the right lighting solution for your plants, you might as well contact us.