Ideal light conditions for growing microgreens indoors?

Ideal Light Spectrum

Microgreens prefer a balanced spectrum with a high concentration of blue and red light, typically 400-700 nanometers (nm) and 700-800 nm, respectively. To replicate this spectrum indoors, use LED grow lights with a balanced ratio of blue and red LEDs. Aim for a PAR (photosynthetic active radiation) value of 200-400 micromoles per square meter per second (μmol/m²s) for optimal growth.

Light Duration and Intensity

Provide microgreens with 12-16 hours of light per day, with the intensity increasing as the plants mature. For the first 1-2 weeks, use a lower intensity of 100-200 μmol/m²s to prevent burning the delicate leaves. As the plants grow, increase the light duration and intensity to 16 hours and 400 μmol/m²s, respectively.

Alternative Light Sources

If you don’t have access to LED grow lights, consider using natural light or alternative sources like fluorescent or incandescent bulbs. Place microgreens near a sunny window or use a grow light with a lower intensity, such as a 20W fluorescent bulb, to provide sufficient light for growth. Monitor the light conditions and adjust as necessary to prevent over- or under-lighting.