How to Choose the Best Grow Lights for Indoor Plants

 Choosing the best grow light for a beginner grower can be a daunting task. A simple Amazon search for “grow lights” will yield hundreds of different grow lights for all types of cultivators. Everything from $5 incandescent lamps to expensive high-tech commercial LED or HID lamps can be found. But which light will best fit your setup? Below is an explanation of how different plant types react to different grow lights as well as a list of some different types of grow lights, their pros and cons, and how you can use them for your indoor growing.

Which light is best for my garden?

When searching for the proper lighting for your indoor garden, a common question that may come up is “Which light is best for my plants?” This question has many different factors to consider before a concrete decision can be made. Firstly, which type of plants do you have in your garden?  If you have plants that are leafy greens, seedlings, or have lots of foliage, it would be best to have lights with cooler spectrum bulbs (6,500 K). If you have flowering or fruiting plants such as citrus, warmer spectrum bulbs (2,500 K) will be best suited.

The next question that you may find yourself asking is “What does K stand for?” K is short for Kelvin, a scale of temperature measurement. Similar to Fahrenheit and Celsius, the lower the number, the cooler the temperature. However, the light spectrum acts oppositely; (the lower the number the warmer the light).

The last piece of information that can be useful to know is what color corresponds to what side of the light spectrum? Warmer light tends to be yellows or reds while colder lights tend to be blues and whites.

What is the light spectrum and how does it relate to my garden?

The electromagnetic spectrum is a wide range of frequencies of electromagnetic radiation. In Layman’s terms, there are invisible waves all around us with different sizes and speeds. These waves are so small that they are measured in nanometers (nm). A nanometer is one-billionth the size of a meter. Some more well-known parts of this spectrum include X-rays, microwaves, and radio waves.

One part of the spectrum that you may not realize is part of it is the visible light spectrum. This portion of the electromagnetic spectrum is the only part visible to the unaided human eye. These waves range from about 400 nm to 700 nm. The classic acronym “ROYGBIV” that was used to remember the colors of the rainbow can also be used to remember the order of the visible light spectrum. Red is at the upper end of the spectrum (700 nm), violet is at the lower end of the spectrum (400 nm) with yellow/green light in the middle (~550nm). You can use this information to better understand which light produces these wave frequencies to provide the correct color of light to your plant.

Why should I use indoor plants grow lights?

Indoor plants grow lights offer several benefits and cultivators have virtually endless options to choose from, according to Michael Zartarian, an engineer at Zartarian Engineering and the RII Technical Advisory Council. "We are living in the golden age of grow lights. There have never been so many high-quality options available to home and commercial growers," he said.