Clients are concerned about the effects this lighting may have on plants in the landscape. To understand how these types of lighting may affect the plant we need to understand how plants use light. The wavelength of 380 nm is visible to us as violet. The wavelength of 760 is visible to us as red. Wavelengths in between are seen as the colors of the rainbow, the light spectrum.
Light controls many plant processes.
Photoperiod responses occur in the red wavelengths. Short-day plants initiate flower buds when days are shorter than a critical point. A more appropriate name may be long-night plant. Long-day plants continue in a vegetative state until day length is longer than a critical point. A more appropriate name for this group of plants may be short-night plant.