Due to the explosive growth of the indoor commercial cannabis growing industry, most of the research and development on how lighting spectrum affects plant growth has focused on cannabis. Cannabis growers generally adhere to a certain spectrum combination pattern:

Growers initially want cannabis plants to establish a strong root structure during the germination and seedling stages. This root structure can be enhanced by varying proportions of red and far-red light at wavelengths of 660 nm and 730 nm.

With more far-red light, cannabis plants grow taller and have fewer leaf nodes. The plant actually needs more red light than far-red, and it has evolved through natural processes to grow taller in order to get its share of red light when it grows in a crowded field of other plants that also need red light. As the cannabis plant grows, growers can change the relative percentages of red and far-red light to achieve the height and leaf ratio of the cannabis plant.

Cannabis plants (like other plants) also require a day-night cycle to develop properly. LED grow light systems are ideal for replicating these cycles because they can be turned on and off almost instantly, with no warm-up phase required. Cultivators can factor these growth photoperiods into the spectral changes used throughout the plant's life cycle.

As the plant approaches its flowering stage, it will require a higher concentration of a mix of all wavelengths of light in the spectrum. Many complex biochemical processes in the plant mark budding and flowering, and these processes all have different spectral requirements.

When the cannabis plant is in the late flowering stage and approaching harvest, light in the blue spectrum can be reduced.

Spectral changes are one of several relevant variables that growers want to control to improve the quality of cannabis production. Light intensity and the temperature and humidity of the growing environment should also be controlled to achieve the [sensitive word] effect.

Huahao Weiye LED plant lights can be designed to achieve different wavelength ratios, and many small LEDs with different wavelengths can be placed on a light board. So when using LEDs, there is no need to mix different types of fluorescent or HID lamps, especially when growing indoors, LED plant growth lights are often the most effective.