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Full Spectrum Light – Grow Lighting using LED

Full spectrum light is a term that has gained significant attention in the field of horticulture, particularly for those involved in greenhouse cultivation, vertical farming etc. As home growers make more use of lighting, understanding is crucial to choosing the correct LED lighting system.

Vertical Farming

Vertical Farming using LED Lighting
Image courtesy: Boyalite

What Does Full Spectrum Light Mean?

Understanding what full spectrum light means, and how it compares to other types of grow lights, such as red-blue grow lights, is crucial for optimizing plant growth and health. This article looks at the concept of full spectrum light, its benefits, and its comparison with other types of lighting, particularly in the context of broad spectrum light and broad spectrum LEDs.

Defining Full Spectrum Light

Full spectrum light refers to light that covers the entire electromagnetic spectrum from infrared to near-ultraviolet, closely mimicking the natural light from the sun. This type of light includes all the wavelengths necessary for plant growth, providing a balanced and comprehensive range of light.

Visible Light in EM Spectrum

Philip Ronan, CC BY-SA 3.0, via Wikimedia Commons

Plants use light primarily in the photosynthetically active radiation (PAR) range, which spans from 400 to 700 nanometers. Full spectrum lights encompass this range, ensuring that plants receive the optimal wavelengths they need for various physiological processes.

Full Spectrum vs. Red-Blue Grow Light

When discussing grow lights, the debate often centres on full spectrum vs. red-blue grow lights. Red-blue grow lights are designed to emit light primarily in the red and blue wavelengths, which are the most critical for photosynthesis. Red light (around 660 nm) promotes flowering and fruiting, while blue light (around 450 nm) encourages vegetative growth and leaf development.

While red-blue grow lights can be effective for specific growth stages, they may not provide the balanced light that plants require throughout their entire lifecycle. Full spectrum lights, on the other hand, deliver a more natural and comprehensive light environment. This balance helps ensure that plants receive the right mix of wavelengths needed for seedling development, vegetative growth, and flowering, all from one light source.

Advantages of Full Spectrum Light

Comprehensive Growth: Full spectrum lights support all stages of plant growth, from seedling to harvest. They provide the necessary wavelengths for photosynthesis, as well as for other processes like photomorphogenesis which is light-mediated development, where plant growth patterns respond to the light spectrum and photoperiodism, which is the response to changes in daylength that enables plants to adapt to seasonal changes in their environment..

Better Plant Health: The balanced light provided by full spectrum lights promotes healthier and more robust plant growth. Plants can grow stronger stems, larger leaves, and more abundant flowers and fruits.

Natural Light Mimicry: Full spectrum lights closely mimic natural sunlight, which can help reduce plant stress and improve overall growth conditions.

About Broad Spectrum Light

Broad spectrum light is similar to full spectrum light. However it is typically used to describe light that spans a wide range of wavelengths, although it might not cover the entire spectrum as comprehensively as full spectrum light.

The broad spectrum lights still offer a more varied range of wavelengths compared to red-blue lights, providing a wider array of benefits for plant growth.

Broad spectrum light can include not only the primary wavelengths for photosynthesis but also other wavelengths that can influence plant health and growth, such as UV and far-red light. This additional range can enhance plant processes like germination, flowering, and secondary metabolite production.

Benefits of Broad Spectrum Light

Enhanced Growth: By providing a wider range of wavelengths, broad spectrum lights can improve overall plant health and growth efficiency.

Versatility: Broad spectrum lights can be used for a variety of plants and growth stages, making them a versatile choice for growers.

Stress Reduction: The more natural light environment created by broad spectrum lights can reduce plant stress and increase resilience.

Broad Spectrum LEDs

Broad spectrum LEDs have revolutionized indoor gardening and commercial horticulture. These lights combine the energy efficiency of LEDs with the benefits of broad spectrum light, offering a powerful tool for growers.

The broad spectrum LEDs are designed to emit a wide range of wavelengths, similar to natural sunlight. They are highly efficient, producing more light per watt of electricity consumed compared to traditional lighting systems. This efficiency not only reduces energy costs but also minimizes heat output, reducing the need for extensive cooling systems in indoor growing operations.

Advantages of Broad Spectrum LEDs

Energy Efficiency: Broad spectrum LEDs use significantly less energy than traditional lighting systems, reducing operational costs and environmental impact.

Longevity: LEDs have a longer lifespan compared to other types of bulbs, meaning less frequent replacements and lower maintenance costs.

Precision Control: Broad spectrum LEDs can be fine-tuned to emit specific wavelengths. This allows growers to tailor the light spectrum to the exact needs of their plants.

Low Heat Emission: LEDs produce less heat, reducing the risk of heat stress on plants and lowering the need for additional cooling systems.


Full spectrum light is a comprehensive and balanced lighting solution that mimics natural sunlight. It supports all stages of plant growth and promotes overall plant health. When compared to red-blue grow lights, full spectrum lights provide a more natural and complete light environment, which can lead to better growth outcomes.

Broad spectrum light, including broad spectrum LEDs, offers similar benefits by covering a wide range of wavelengths. Broad spectrum LEDs, in particular, combine the advantages of broad spectrum light with the energy efficiency and longevity of LED technology.

Understanding the differences between full spectrum, broad spectrum, and red-blue grow lights is helpful It allows growers to make informed decisions about their lighting setups, ultimately leading to healthier plants and more successful harvests.

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