Plant Lights & Cactus

Type of Lighting

• There are several artificial light systems available for indoor growers. One common type of artificial grow lighting that works great with cacti is a high intensity discharge (HID) system. Metal halide lamps and high-pressure sodium lamps are the two best HID systems available. Desertgardens.com suggests using metal halide lamps to grow your cacti because of the heat and UV radiation they produce. You can also use fluorescent lamps to grow cacti but you will not see as much growth as you will if you use an HID system.

Placement

• How far you place the bulb from your cacti is crucial and can depend on what type of lighting system you decide to employ. The minimum level of light required to grow cacti indoors is 15 watts per foot. This means that fluorescent lamps should be placed 12 to 15 inches from the top of the cacti. HID systems however, should be placed considerably further away but that distance depends on the wattage.

Length of Lighting

• Cactusinfo.net suggests that you give your cacti 12 to 18 hours of artificial light a day. An electronic timer is a great asset if you are growing plants under artificial plant lighting systems because of the precision and convenience it provides. In the winter, you should reduce the amount of lighting so the plant gets 12 or more hours of darkness. Dark periods in the winter are especially important if you have a flowering variety.

Frequency

• Plants have a preferred light frequency (colors) and cacti are no exceptions. Cacti prefer light frequencies that are in the red to blue side of the light spectrum. Fluorescent lights will provide this frequency but for the best results, use a metal halide bulb to produce more light in the ideal spectrum.

Other Keys for Success

• There are several things you can do to get the most out of your artificial plant lighting. Attach reflectors to the lighting system to focus more of the light on the cacti. In addition, rotate your cacti every two weeks for maximum results.