Grow Lights: Artificial Sun for Indoor Gardens

Grow Lights: Spectrum, Intensity, and Duration for Plant Growth

Grow lights mimic sun spectrum when natural light is insufficient. Orchids, African violets bloom year-round; herbs, greens grow indoors. Red → flowers/vegetative growth; blue → foliage. Intensity = wattage × distance. Some need 10–12″; others 36″. Plants need rest—don’t run 24/7. Categories: short-day (12 hr), day-neutral (8–12 hr), long-day (14–18 hr). Types: fluorescent (cheap, 2–3× incandescent), full-spectrum fluorescent (balanced), metal halide (intense bluish-white, popular), high-pressure sodium (yellow-orange → fruit/flowers), LED (new, efficient, cool, long-lasting).