How to Select and Effectively Use Grow Lights for Indoor Houseplant Gardening

The summer months are readily approaching. For many gardening enthusiasts, it’s just about time to bring those houseplants back indoors to shield them from the brutal summer heat. Others may have purchased some new plants during the spring plant nursery frenzy and aren’t quite sure how to provide them with adequate lighting.

If your natural window lighting is lacking for your beloved houseplants, consider supplementing your light dynamics with artificial lighting!

Grow lights allow us to cultivate various plants indoors, regardless of the season or available sunlight. They use a specific ratio of wavelengths, mostly in the red and blue spectrums, which are ideal for helping plants photosynthesize.

Thus, regular household lights are not suitable for supplementing plant light. They operate on spectrums that do not promote photosynthesis.

Decent grow lighting fixtures are more affordable than one might expect, and they’re extremely handy for combating dark winter months, growing high-light plants, placing plants in windowless rooms and nurturing fragile plant propagations!

When selecting a grow light for your plants, note that their effectiveness depends on the intensity of the lamp (or the photosynthetic photon flux density, or PPFD) and the wavelength (or the spectrum of light, known as photosynthetically active radiation, or PAR).

Other crucial factors to consider include the proximity of the light source to the plants, how much natural sunlight the plants are also exposed to, and the time of year the plant “thinks” it is, based on available supplemental light.

Learn the three dominant types of grow lights.

Grow lights should be carefully selected depending on the specific plant(s) you’re growing. As you may have noted from the “window” spiel, this can get pretty complex. Here are the basics.

There are three primary kinds of lights for indoor plant use: fluorescent, low-power LEDs and high-power LEDs.

Fluorescent lights are a popular choice of supplementary plant lighting. Pegged as the “old-schoolers” of the grow light world, these sources used to dominate indoor lighting supplements until LEDs entered the arena. They don’t last as long as LED lights, and are bulkier and less sustainable, but they’re easily accessible and a fine option.

These lights are available in different styles, including tubing or spot lamps. Tubing lights are hung from the ceiling or a frame and will have a reflective background. Spotlights can be placed directly in your plant pot and are extended to shine over its foliage.

Experts recommend HO T5 fluorescent lamps, which produce less heat than old school bulbs, and are more energy efficient. The light fixture contains a ballast that generates heat, so one section of the lamp will be hotter than the rest. If you opt to use fluorescent lighting, carefully watch plants placed underneath for signs of heat stress.

LED lights consume less electricity and live longer than fluorescent lights, but quality fixtures are often more expensive. The biggest hurdle with LEDs is determining if their intensity is adequate for your plants.

Low-power LEDs are the inexpensive ones that saturate your Amazon search. They’re typically fine lighting supplements for foliage houseplants or small succulents, but they’re insufficient for plants with intense light requirements, like edible plants (i.e., tomatoes, citrus and herbs). Many emit a pink or purple color, but if this doesn’t match your preferences, opt for LEDs with a full or broad spectrum of white-colored light.

High-power LEDs are ideal candidates for edible plants, larger floor houseplants, and pretty much any plant that isn’t directly placed on a windowsill. You get what you pay for, and ample light intensity (PPFD) is more expensive.

Pro-tip: Also consider the light spectrum! Grow lights are broadly divided into “cool” and “warm” spectrums. Cooler lights (>5,000K) are most ideal for leafy growth, while warmer lights (<5,000K) promote more flowering. This said, most plants grow well under a balanced, broad-spectrum grow light.

Select the best grow light and utilize it effectively.

Now that you’re aware of the fluorescent, low-power LED and high-power LED grow light options on the market, weigh the following considerations when choosing your artificial sun!

Before hitting “place order” on any crazy purchases, determine what exactly you want to do with your light. Consider its potential placements in your home, as well as which plant(s), along with their specific lighting requirements, you’d like to place underneath it.

Our houseplant natural lighting guide will help you choose which plants you’d like to light supplement, as well as how much additional support they’ll need! Remember that nicer, pricier lights may only need to shine for a fraction of the time as their cheaper counterparts.

Thus, seedlings grown from scratch may benefit from a splurge on really bright lights, whereas low-light houseplants may be fine underneath thrifty lamps, with a bit of supplemental window lighting.

Once you have your lights, position them close to your plants! Generally, the closer to the crop, the more of that light will actually be used by the plant. This varies by plant and by lamp, but six inches is a good rule of thumb. If the light is placed a foot or two away, its effectiveness decreases dramatically.

Don’t underestimate the power of simply eyeballing your plant. Similarly, to gauging sunlight, you can quite literally see the amount of light shining around your plant, as well as the areas it is (and is not) shining. Plan to turn your plants regularly to prevent unattractive growing tendencies, like inconsistent leaf growth and long, veiny, leafless limbs on vine plants.

Additionally, use a timer! Ideally, you’re aware of your specific plant’s lighting needs. If you have a plant that is day-length sensitive, inconsistent lighting exposure (i.e., four hours one day, and sixteen the next) can dramatically stunt or harm your plant’s growth. Many grow lights can be purchased with built-in timers to give you control over your plant’s day-length.

And if you’re not aware of the light your plant needs, research these. As mentioned above and in our houseplant natural lighting guide, your plant’s lighting dynamics will be influenced by many factors. Some of these include its distance from artificial light, distance from windows, reflective objects in the room that light may bounce from (i.e., mirrors), and light obstruction from other objects (i.e., plants clustered together).

Factor these considerations along with your plant’s specific lighting requirements when deciding how much supplemental, artificial light your plant will receive. For instance, most herbs have high light, full-sun requirements. If placed along a bright windowsill, they could benefit from grow lights for around 14 hours a day, in addition to sunlight. If they receive no sun, their artificial light “day” might be 22 to 23 hours long.

Mimic the day length your specific plant is used to, if your plant is sensitive to this. Consistent day-lengths, and their counterpart, night-lengths, aren’t particularly important for all plants, but they are a fundamental health factor for some. Predictable and appropriate day and night-lengths are essential for plants like basil and Christmas cacti. Other plants, such as tomatoes and petunias, are day neutral.

Mimicking natural day and night-lengths is a fairly advanced, niche gardening techniques. If this information isn’t readily available online for your specific houseplant, it might not matter much. Yet, as with all other house-environmental factors, a good rule is to simply try to recreate your plant’s native habitat as well as you can.

Lastly, make sure your plants are getting adequate water! Plants which aren’t receiving adequate light will not use as much water. Overwatering heavily shaded houseplants is a recipe for the infamous killer, root rot.

As you increase the amount of light they’re exposed to, your plants might start to require more water. Utilizing a moisture meter is the best way to track their changing water needs. Many meters have built in light meter features, to evaluate your grow light handiwork!

Good luck, and happy gardening!

Support Christian Journalism

Freedom ​is Not Free! Free Speech is essential to a functioning Republic. The assault on honest, Christian Journalism and Media has taken a devastating toll over the last two years. Many Christian media outlets have not survived.

It is through your Generosity and Support that we are able to promote Free Speech and Safeguard our Freedoms and Liberties throughout our Communities and the Nation. Without your donations, we cannot continue to publish articles written through a Biblical worldview.

Please consider donating or subscribing today. A donation of any size makes a Big Difference. Thank you for your Support!

Hannah Menslage

Hannah Menslage is the assistant publisher and editor of Katy and Fort Bend Christian Magazines. She also writes a lifestyle column and manages the social media accounts for these publications. Hannah is a journalism/communications student in the Valenti school at the University of Houston. In her free time, Hannah enjoys gardening, cooking and baking, hanging out with her dog and cat, writing and completing fun DIY projects. Contact her with any questions at