LED Grow Light Spectrum Guide: What You Need To Know About Light Spectrum

When it comes to the lighting requirements for various plants and growth situations, the light spectrum is crucial. The grow light spectrum necessary for lucrative plant yields will vary depending on the climate, the type of lights utilized, and the plants themselves. Choosing the best growth light spectrum for your indoor plants might be overwhelming. You've probably heard of "colour temperature" and are curious about what the optimum range is for different plant growth stages. To fully exploit the potential and possibilities of a well-designed LED grow light setup, you must first understand what LED grow light spectrum is necessary and how to tailor it to your specific environment.

LED Grow Light Spectrum

If you're looking for the best LED grow light spectrum for your indoor garden, keep reading this article to find out what you need to know about LED grow light spectrum. We will discuss some of the fundamentals of the light spectrum and how it influences plant development so that you may select the finest LED grow light for your indoor garden.

Color Spectrum

A colour spectrum is a graphical depiction of all of the colours found in light. Scientists now utilize wavelength numbers to measure colour, a far more exact approach than using colour names to describe it. A red's wavelength might be 630 or 660. We perceive red in each of these, yet they are not the same colour.

Red light, or wavelengths between 630 and 660 nm, is required for leaf expansion and stem development. Furthermore, this wavelength regulates seed germination, dormancy periods, and blooming.

Because too much blue light (400-520 nm) may inhibit the growth of some plant species, blue light must be properly combined with light from other spectrums. Blue light affects both the quantity of chlorophyll in the plant and the thickness of the leaves.

Green light (500-600 nm) penetrates the upper canopies' thick coverings to sustain the bottom canopy's leaves.

Far Red Light (720-740 nm) penetrates thick top canopies as well, promoting the formation of lower-canopy leaves. When a plant is exposed to IR light, it takes less time to bloom. Far red light also encourages plants to produce bigger leaves than plants that do not receive this sort of light.

Spectrum of LED Grow Light

The light spectrum is the range of wavelengths radiated by a light source. When discussing the light spectrum, the term "light" refers to the visible region of the electromagnetic spectrum 380-740 nanometers (nm). Wavelengths in the infrared (700-106 nm), far-red (700-850 nm), and ultraviolet (100-400 nm) bands are included in radiation. Growers are especially interested in the wavelengths that are crucial to plants. Plants detect the visible spectrum (380-740 nm), which includes PAR (400-700 nm) and far-red light, as well as UV radiation (260-380 nm) (700–850 nm). Indoor and greenhouse environments will have different light spectrums in horticultural applications. The spectrum of your grow lamp will cover the whole light spectrum received by your plants in confined settings. In contrast, you must consider that your plants in a greenhouse are exposed to both grow lights and the sun's spectrum. In any instance, the amount of each waveband received by the plant will have a significant influence on growth.

Florescent bulbs are either warm white or cold white in the grow light spectrum. While this was useful for fluorescent lights, LED grow lights did not respond well to such designations. It is more appropriate to talk about LEDs in terms of wavelengths and to demonstrate the whole colour range.

Plant Growth and the Color Spectrum

Plants require light to grow, but the quality of light is just as crucial as the amount. Plants can only absorb a restricted range of light's spectrum. Plants use a light spectrum known as Photosynthetically Active Radiation (PAR) with wavelengths spanning from 400 to 700 nm. As a result, light generated outside of this spectrum cannot be absorbed and used by plants for growth.

Furthermore, different light wavelengths may cause the plant to react in different ways. Red light, for example, is beneficial for growing plants in general, but when used solely, it can result in "stretched" plants that are tall with sparse leaves. Increasing the quantity of blue light during the vegetative state can result in more compact, stockier plants that have a more level canopy height and get similar amounts of light. During the flowering stage, the plant's growth rate is then boosted by the addition of additional red light, which "stretches" the plant and provides bigger yields. This is because a plant's response to the spectrum of light it gets in nature conveys certain environmental factors, such as the season. As a result, having a "full-spectrum" grow light with a diversity of light wavelengths is critical.

Increasing the quantity of particular light colours might assist your plant grow depending on the stage of development it is in. Once you understand how different wavelengths cause distinct plant responses, it's easy to see why full-spectrum lights are the ideal for plant development. Full-spectrum lighting mimics natural sunshine by combining all colours at all stages of development.

Light Spectrum for Plant Growth

A plant bending toward a light source is an example of photomorphogenesis. Light also influences plant growth phases, including germination and blooming. Plants mostly require light in the 400-700 nm range for photosynthesis. This light spectrum is known as Photosynthetically Active Radiation (PAR), and it contains red, blue, and green wavebands.

Photomorphogenesis occurs throughout a larger wavelength range, from 260 to 780 nm, and includes UV and far-red light. Plants contain photoreceptors that, when stimulated by photons of certain wavelengths, can cause varied growth characteristics. So, by manipulating the light spectrum, you may cause significant changes in plant development.

The following growth aspects can be influenced by the light spectrum:

  • Flowering fruit yield

  • Plant development Color Flavor Nutrition

  • The rate of growth

  • Compactness of new weight

It's crucial to remember that activating plant responses with light is just one part of a bigger process. The outcomes are significantly influenced by a range of parameters such as light intensity, photoperiod, growth habitat, plant species, and even plant variation.

Choose the Right Light Spectrum

The optimal colour spectrum will be determined by your growing objectives. As plants develop and progress through their life cycle from seedling to adult, then blooming and fruiting, the best LED grow light changes. As a result, the appropriate colour spectrum will be influenced by the plant species you choose. Remember that plants gain the most from all wavelengths of light in general, but they do not require equal quantities of each.

The Colour Spectrum Optimal for LED Grow Lights

It should be similar to the spectrum required for plants. Green, yellow, and a lot of blue and red in general. It would be much great if you included some near IR and perhaps even some near UV. Before purchasing a grow lamp for your indoor garden, carefully verify the light's output spectrum. Crop yields produced using HPS grow lights may now be equaled, if not exceeded, by new LED grow lights that provide a white, full-spectrum light.


RayonLED has strived to optimize the spectrum of our LED grow light fixtures in order to maximize the productivity and quality of your grows. RayonLED offers the greatest LED grow light at a great price. Check out our latest deal on LED grow lights.