LED spectrum for cannabis: blue light 400–500nm drives vegetative growth, red 600–700nm promotes flowering — optimise spectrum for each growth phase.
Different light spectra promote different stages of development. Blue light (400-500nm) stimulates vegetative growth, red light (600-700nm) promotes flower formation. UV-A (315-400nm) increases resin production. Infrared (700-800nm) lengthens internodes. Optimum spectra: vegetative 6500K with high blue component, flowering 3000K with red emphasis, finishing with UV-A addition.
A light spectrum with a high proportion of blue light (400–500 nm) is ideal for the vegetative phase, as it promotes the growth of leaves and stems.
During the flowering phase, the light spectrum should contain more red light (600–700 nm) to promote flower formation and increase yield.
Light intensity is crucial; too little light can inhibit growth, while too much light can cause stress and burns. The optimal intensity varies depending on the growth stage.
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