LED Grow Lights Vs. HID

Grow lights may be used to supplement natural lighting in greenhouses.

Grow lights are a way to supplement natural lighting in grow rooms, greenhouses, or in the living area of a home. Two choices for grow lights are high-intensity discharge (HID) lamps and light-emitting diodes (LED) lamps.

HID Lamps

HID lamps include both metal halide and pressure sodium lights. Both types of lights produce sufficient light for photosynthesis. Gardeners also find it easy to switch between the two to match or control a plant's growth cycle. But the lamps waste a lot of energy and generate a lot of heat.

LED Lamps

LED lamps are more energy efficient than HID lamps. They are less bulky because they do not require cooling equipment or reflective hoods. The diodes may be adjusted to match the color temperature ranges of light that plants use most. But more lamps are required to generate sufficient light for plants to undergo photosynthesis.

Effects

Gardening practices must be changed if a gardener is switching from HID lamps to LED lamps. Plants must be watered and fed less because the lack of heat that warms plants from HID lamps means that plants use less water and fewer nutrients. Gardeners who do not adjust their watering practices are prone to over watering plants.

References

• Grow Light Express: LED Grow Lights: Ready for Prime Time?
• Iowa State University Extension: Lighting & Houseplants; Cynthia Haynes; 2006
• University of Missouri Extension: Lighting Indoor Houseplants; David Trinklein; May 2002

Resources

• University of Alaska Fairbanks: Lighting Your Greenhouse; 2010