What Is a Grow Light?
This gardening tool is here to keep your houseplants healthy and happy.
Do you enjoy having plants on your window sill? Would you love to grow produce from the comfort of your kitchen?
Whether you want to grow seedlings and edibles indoors or you just want to keep your houseplants thriving all year round, a grow light is an essential indoor gardening tool.
What Is a Grow Light?
A grow light is an artificial light that helps indoor plants grow in every season. Wondering how it works? Here's a quick science review: Plants need water, carbon dioxide, and light to grow. They take in water through their roots, carbon dioxide from the air, and light from the sun. With these three ingredients, plants can perform photosynthesis – a process that produces the glucose and oxygen they need to survive.
But what happens when your plants don't have access to sunlight, or when access is limited? That's where grow lights come in. Grow lights mimic the sun, stimulating photosynthesis and encouraging plant growth. By providing your plants with a healthy amount of photosynthetic light from a grow light, you can ensure they grow healthy and strong.
When to Use a Grow Light
The more sunlight a plant a requires, the more it can benefit from a grow light. And if your plant is looking stretched, weak, and thin, it's probably not getting enough light.
Here are a few types of plants that can benefit from a grow light:
- Fruit-bearing plants (e.g., tomatoes)
- Vegetable-bearing plants (e.g., carrots)
- Flowering plants (e.g., geraniums)
- Herbs (e.g., basil)
- Succulents (e.g., cacti)
Take a look at some of the most popular types of grow lights:
LED Grow Lights: LED (light-emitting diode) grow lights have a long lifespan and a low heat output. Plus, they're energy-efficient, shatterproof, and mercury-free.
Best for: All types of indoor gardening
Fluorescent Grow Lights:Fluorescent grow lights are available as long, tube-like bulbs as well as compact fluorescent bulbs. These types of grow lights are typically inexpensive and easy to use.
Best for: Plants with low to medium light requirements (e.g., African violets)
HID Grow Lights: High-intensity discharge (HID) grow lights do a great job replicating natural light, but they're expensive to purchase and operate, and they're incredibly hot. There are two main types of these high-output lights: high-pressure sodium lights that emit a red color, and metal halide lights that produce a blue color.
Best for: Commercial grow rooms
Plants need light to survive, but a regular desk lamp isn't the best option to keep your greenery growing. Grow lights, on the other hand, are specially designed to provide the proper color spectrum, temperature, and intensity needed for photosynthesis.
Color spectrum: The light spectrum includes a range of wavelengths, which we see as colors. Grow lights emit light on the same wavelengths as the sun, providing plants with what they need to grow. Red light is particularly good for fruiting and flowering plants, and blue light is best for vegetative plants. Regular incandescent lights provide more light in the yellow and green spectrums, which is less helpful for plant growth.
Temperature: Regular incandescent lights emit a higher percentage of heat than grow lights – and excessive heat can burn your plants. If you use incandescent lightbulbs, be sure to keep your plants at least 24" away to prevent heat damage. LED grow lights can be as close as 6" from plants, and fluorescent and HID grow lights can be as close as 12".
Intensity: Regular incandescent lights are not as effective as grow lights, which have been specifically designed to deliver more intensity so plants have sufficient energy for growth. You can find grow lights in a variety of light-intensity options based on the needs of your plants. You may even be able to adjust the intensity of the grow light.
Grow Light Features
Shopping for a grow light? Check out our guide to the 8 Best Grow Lights for Plants, and keep these key features in mind:
Size: If you have several plants, consider purchasing a larger grow light or one with multiple lamps. Some grow lights feature height-adjustable lamps so you can create the right amount of distance between the light and each individual plant.
Automatic Timer: Plants shouldn't be exposed to constant light, so many grow lights include an automatic timer to ensure your plants get at least 8 hours of darkness and 8 to 16 hours of light.
Flexible Lighting: Some grow lights offer various lighting modes and brightness levels so you can adjust them to provide the appropriate amount of light at each stage of plant growth.
If you want to enjoy your houseplants all year round, grow lights that supplement natural sunlight can keep your greenery healthy and happy. And now that you can confidently answer the “What is a grow light?" question, you can shop for the one that best meets your horticultural needs.
Article by Robyn Tellefsen
