How to Use Grow Lights for Indoor Plants

Grow light placed over potted variegated pothos plant on white desk

The Spruce / Anastasiia Tretiak

Is your home light-challenged? Or perhaps you have just run out of window space for that extra plant you just had to have? No need to watch your indoor plants slowly wither away, adding a grow light to your indoor plant setup is a great way to support strong, healthy growth in your plants. Once reserved for commercial growers and hobby farms, grow lights are now widely available in a range of different styles, sizes, and strengths designed for residential use. So if you are struggling with a lack of natural light in your home, a grow light is a great solution—trust us, your plants will thank you!

Benefits of Grow Lights

Indoor plants require more light than most homeowners realize, and a lack of natural light is an all-too-common houseplant ailment. Grow lights are used to increase the amount of usable light available to indoor plants which can help increase nutrition, speed up growth, accelerate flowering, and frankly just keep your houseplants alive and healthy indoors.

How Do Grow Lights Work?

Unfortunately, while traditional light bulbs keep our homes nice and bright for us, they don’t benefit our plants, which require very specific types of light in order to grow. On the spectrum of visible light, the best wavelengths for photosynthesis occur at the blue range (425 to 450 nanometers) and the red range (600 to 700 nanometers), while traditional light bulbs fall right in the middle (500 to 700 nanometers). Red light supports flowering while blue light supports vegetative and structural growth. However, both types of light are essential to supporting balanced, healthy plant growth. Grow lights provide indoor plants with the type of light that they need in order to photosynthesize. They can either mimic the full light spectrum of the sun (called full-spectrum lights) or emit specific wavelengths in the blue or red ranges.

Types of Grow Lights


Incandescent grow lights are the cheapest but also the least energy-efficient option available. They have a relatively low light output, however, their high heat output means they can’t be placed too close to any plants. Incandescent bulbs produce more red light than blue light.


Fluorescent grow lights are more energy-efficient than incandescent lights, however, they tend to be more expensive. They produce a decent spectrum of light for plants and have a lower heat output than incandescent bulbs. However, they can be fragile and don’t last as long as some other lights available, such as LEDs. Fluorescent lights are usually sold as tube lights, which is usually not as convenient for lighting just a few indoor plants at a time.

LED (Light Emitting Diode)

LED grow lights are energy-efficient, cost-effective, and provide an ideal light spectrum for all types of plants. Plus, they have a low heat output, so you won’t need to worry about burning your plants if you place the light too close. 

High Intensity Discharge (HID)

Most commonly used for large-scale commercial growing operations, high intensity discharge (HID) lights have an extremely high light output. They are also expensive and typically sold as large-scale installations versus small individual bulbs.

What Type of Grow Light is Best?

With so many options available, choosing a grow light for your plant can quickly become overwhelming. The good news is that for most residential, small-scale applications, and full-spectrum, LED grow lights are the best choice. Not only are they cost-effective, widely available, and energy-efficient, but they offer an ideal light spectrum range for your indoor plants. 

LED grow light placed over succulent with circular leaves

The Spruce / Anastasiia Tretiak

Where to Put Grow Lights

The closer a grow light is to a plant, the more light the plant will receive. Ideally, a grow light or bulb should be placed within a couple of feet of a plant to ensure it receives enough light. It is usually also best to place the light directly above a plant, rather than off to the side as this could cause the plant to grow sideways and “reach” towards the light. However, for some plants, such as trailing plants, for example, having the light directly above the plant isn’t as important since they don’t grow upwards anyways. 

Circular grow light hovering above variegated pothos plant

The Spruce / Anastasiia Tretiak

How Long to Leave Grow Lights on

Grow lights should be left on for at least 8 to 10 hours a day, which mimics the amount of natural sunlight plants are typically exposed to within a day. Putting your grow lights on timers can help to automate this process so you don’t accidentally forget to turn your lights on or off. You can find light timers at most big box stores or online.

Grow light timer next to succulent leaves

The Spruce / Anastasiia Tretiak