Plantlights

Plantlights are artificial light sources used to provide light energy for photosynthesis in plants when natural daylight is unavailable or insufficient. They are common in indoor gardens, propagation racks, greenhouse stabilization, and vertical farming, where they supplement or replace sunlight to regulate growth and improve yields.

The main technologies are LED, fluorescent, and high-intensity discharge lamps. LEDs are widely used in modern horticulture because they are energy-efficient, generate relatively little heat, and can be spectrally tailored. Fluorescent fixtures, such as T5 tubes, are inexpensive and suitable for seedlings and low-light crops. HID lamps, including metal halide and high-pressure sodium, deliver high light output but require more electricity and cooling and are being replaced in many home systems by LEDs.

Plants respond most to red and blue light, but many fixtures provide broad spectra to approximate natural light. Light intensity is measured as photosynthetic photon flux density (PPFD) and is affected by distance between the fixture and canopy. Common target ranges are roughly 100–200 PPFD for seedlings, 200–400 PPFD for vegetative growth, and 400–800 PPFD for flowering and fruiting, though species vary widely. Photoperiods typically range from 12 to 16 hours of light per day for many crops; some plants require shorter or longer days.

Other considerations include energy efficiency, heat management, and uniformity of light distribution. Lamps have different lifespans and maintenance requirements; LEDs often last many tens of thousands of hours. Positioning, cooling, and timers help conserve energy and avoid overexposure or leaf burn.

Plantlights enable year-round production, seedling propagation, and research in environments where natural light is unreliable or limited.