The Best Grow Lights, According To Our Testing

The Bottom Line

If you are looking for versatile grow lights that offer easy operation, we recommend LBW LED Grow Light With Stand because it can be set up in just over two minutes, includes extra parts for mounting to the ceiling, and has an integrated timer with adjustable settings to maximize plant growth.

If you want a model with more bells and whistles that makes growing seedlings or overwinter plants effortless, choose the AeroGarden Trio Grow Light. Its intuitive app allows you to schedule the amount of light that your plants get, as well as the type of light for your tender seedlings. 

Our Testing Process

We rounded up 16 of the best grow lights and put them through a series of tests. We planted six seed packets (basil, tomatoes, spinach) in six separate pots with grow lights used on three and only natural sunlight from windows on the other three. We placed the three grow light plants in a room that does not get much sunlight and placed the other three in a room that gets a fair amount of natural sunlight.

Each plant was tended identically throughout the testing period, including planting them all with the same potting soil. We tracked their progress over six months and documented all changes in height.

In addition to the growth measurements, we also tracked and observed the ease of setting up the grow light, the clarity of included instructions, how much space the grow light takes up, and how much extra light it adds to the room.

We also evaluated each set of grow lights for color of light, whether they had timers and how well they operated, how warm the grow light felt, whether an app was included and the ease of its operation, and whether the grow light had adjustable settings.

Finally, we tracked the environment each set of plants experienced, including time and intensity of grow lights versus natural light source, the average temperature and humidity in both locations. In the end, we took all ratings across tests and evaluated the value of each model of grow lights. 

Tips for Choosing the Right Grow Lights

Type

Many configurations and styles of grow lights are available on the market. Tabletop units are great for small spaces or a limited number of plants, while hanging or panel lights suit larger plant collections.

Bishop says, “grow lights can be placed anywhere, and there are many options on the market. Ranging from a tabletop arm light to 48-inch shop lights hung from baker’s racks, grow lights come in a range of sizes and can be easily manipulated to fit most home gardener’s circumstances.”

She adds this insight, “Seeds need only warmth and moisture to germinate, and have all the initial food they will need contained in the first set of leaves (called the cotyledons). Because photosynthesis doesn’t commence until the plant produces its first set of ‘true’ leaves, lights can be completely omitted until that point.”  

Size 

When considering size, evaluate the growing space you need to cover—the light should cover the entire growing area. Bishop adds, “Plants need the light source placed only 2-3 inches above the top growth point, so look for lights that can adjust as the plant grows. Second, be sure that the outer seedlings are covered by the light source as well as the center. Invest in a light that is large enough to cover the entire tray of seedlings. And third, buy a simple timer. This will alleviate the dual problems of too much or too little light.”

Bulb Type

There are really three types of bulb: LED, fluorescent, and incandescent. All of the grow lights on our list utilize LED—they are more efficient, offer ideal light spectrum ranges, and emit less heat.

Fluorescent lights tend to be the middle of the road as far as prices go and perform with more energy efficiency than incandescent, the least expensive, most energy inefficient, and highest heat emitting. 

Color

According to Bishop, “While plants utilize the entire light spectrum to photosynthesize, the predominant color used to promote plant growth should be dictated by where the plant is in its growth cycle.”

She adds, “The most utilized wavelengths during photosynthesis are red and blue light. Red light promotes germination & flowering, and would be most appropriate for seedlings, while blue light controls leaf thickness and root development, and would be best used where vegetable growth is needed.”

Wattage

In general, the higher-wattage lights are more intense and better for growing larger areas. But, the wattage your plants need depends on many other factors like plant type, what age they are, and how dense their foliage is. Most experts recommend somewhere between 32 and 40 watts per square foot for the best growth.

Sometimes the term PPFD (photosynthetic photon flux density) may appear on the grow lights’ label—it refers to the amount of light the grow lights give off. According to a 2020 study, 200–900 PPFD is optimal for plant growth, depending on their growth stage. But don’t be alarmed if PPFD is not listed; not all models have them on labels.

We found that lights were often too bright for the space in which they were placed, but the plant needed the brightness for proper growth, making placement an important consideration when shopping for grow lights.

More Grow Lights to Consider 

GE Grow LED Light Bulb: This grow light scored high for setup and brightness, and we especially liked the height recommendations for different varieties of plants, plus the LED light never got hot. Across our tests with basil, spinach, and tomato seedlings, we found the stems of the grow light plants were thicker and sturdier than the natural light plants, though plant height was inconclusive. We appreciated there was an available adjustable light stand for purchase at an affordable price, making this model easier to place, and the light the bulb provides is neither too bright nor too dim for seedlings. It’s a basic setup, but gets the job done.

Questions and Answers

What colored lights promote plant growth?

Maynard weighed in on this one: “Blue light encourages vegetative growth: strong stems. lush leaves and dense roots. Red light promotes flowering and fruit.  For all purpose growing of seedlings, houseplants, and herbs a ‘full spectrum’ bulb is the best choice. Full spectrum bulbs will generally be between 5000 and 6500 K (K= Kelvin). Kelvin measures color temperature or light appearance in a light bulb on a scale from 1,000 to 10,000. The full spectrum bulb will best mimic a bright natural sunlight appearance by emitting the same wavelengths of light that we receive from the sun's light spectrum.”

Will a fluorescent light work as a grow light?

All our experts agree that fluorescent light works as a grow light. But they have a few caveats. According to Maynard, they should be used on plants requiring low to medium light, but she adds LED grow lights have a longer life span, are more energy efficient, and produce better plant health and growth.  

Where should you put grow lights?

The goal of grow lights is to augment where natural light is insufficient. Maynard recommends, “...grow light should be placed about 1 to 1 1/2 feet between the plant's canopy and the grow light.”

She adds this tip, “A simple way to check is to place your palm approximately 6 inches away from the plant's leaves. If your hand is visible your plant is getting enough light. If your hand is not visible, move the plant closer to the light.” 

How long should grow lights be on?

According to Maynard, most plants need 10-12 hours of light per day with at least eight hours of darkness for optimal growth. She adds, “During the darkness plants ‘rest’ and use this time to move nutrients to their extremities while taking a break from growing. Keeping the light on 24/7 can stunt growth and plant tissue and cause the plant to die. Look for grow lights that have on/off timers to help mimic the natural day/night hours of the sun.” 

Bishop agrees that grow lights should mimic nature. She adds, “Seedlings benefit from more light exposure. However, more mature plants that are putting on vegetative growth will need 8-10 hours per day. All plants, regardless of stage, benefit from a respiration period where they can take a break from photosynthesis in complete darkness.”  

Why Trust Southern Living

Carrie Honaker is a food and travel writer who grew up on a farm and has owned her share of grow lights as she moved around the country. As a restaurateur and avid home cook, she has maintained an active herb and vegetable garden at home—she knows the importance of the right amount of light for fragile seedlings, even in her abundant natural sunshine home state of Florida. To compile this list, we tested 16 of the best grow lights available, evaluating them based on ease of use, design, performance, and value. Carrie also spent hours researching what to consider when shopping for grow lights, including size, bulb types, wattage, and included features. For expert tips on what to look for in grow lights, she spoke to Jenny Maynard, owner of The Salt Shed in Panama City Beach, Florida, and Meredith Bishop, owner of Bloom & Bounty in Nashville.