Whether you live in an area with cold, dark winters or your windowsills are just too narrow to hold a flowerpot, grow lights can be a gardener's lifesaver. Even a small, simple setup can allow you to start seeds early, nurture sensitive exotic blooms or maintain a year-round herb garden. When choosing a grow-light system, energy efficiency is a major factor, as these lights will be on up to 12 hours a day. Cost and effectiveness also bear consideration, because you want maximum growth for your money.
The efficacy of a lightbulb is determined by the amount of light it produces for each watt of energy used. Both fluorescent and LED lights vary according to type, with straight-tube fluorescents and cool white LEDs being the most efficient. Circular fluorescents and warm white LEDs are the least efficient. LED lights tend to last longer than fluorescent bulbs, producing less waste. Fluorescent light quality declines long before the bulb burns out; fluorescent bulbs should be replaced when the ends of the tube begin to darken, usually annually.
Both fluorescent and LED grow lights come in warm and cool varieties; plants need both warm and cool light to grow appropriately. Installing only cool light results in tall, spindly plants, while installing only warm light results in a short, bushy plant with no blooms. Indoor gardeners have worked around this effect for years by fitting a two-tube fluorescent fixture with one cool bulb and one warm bulb, or you can opt for a full-spectrum fluorescent tube that emits both warm and cool light. LED manufacturers have sidestepped this problem by combining individual warm and cool LED diodes into a single bulb, which allows it to emit a beneficial light balance. These types of lights are sold as specialty grow lights, not regular indoor LED bulbs.
Fluorescent grow lights have been the indoor gardening standard for decades because they work. Master Gardener Edward Leonard of the University of Maryland College of Agriculture trial and error only can help make that determination.
Fluorescent grow lights are the cheaper option: cool tubes are the least expensive, but you must also purchase the slightly more expensive warm tubes for light balance. Specialized fluorescent bulbs like the full-spectrum or the T-5s command an even higher price. LED grow lights are more expensive initially, but because they must be replaced less often, they may be less expensive over time. When choosing a grow light system, keep in mind that the fixture may be a onetime cost, but the price of the replacement bulbs affects you again and again.
Angela Brady has been writing since 1997. She works as a certified personal trainer, weight-loss consultant and sports nutritionist. A lifelong dancer and yoga devotee, she has competed in gymnastics, swimming, volleyball, softball and soccer. She is also an authority on sustainable design, having studied, practiced and written extensively on the subject.
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