Artificial Lights for Plants: Your Complete Guide

One of the first things we learn about plants is that they need light to grow. However, our homes don’t always provide the type or amount of sunlight plants need. That’s where artificial lights for plants can be beneficial. In this guide, I’ll run through everything you need to know about growing houseplants with artificial lights, including the best types of grow lights, the most suitable plant types, how to set them up, and the most common problems to mitigate. 

Ultimate Guide to Growing Houseplants with Artificial Light

Artificial Lights for Plants – 5 Key Takeaways

When you don’t have adequate natural light, you can use artificial lights to grow a variety of flowering and tropical houseplants. The type of plant will impact the ideal light spectrum and intensity. You must also match the light’s position and hours to meet your plant’s needs and avoid scorching the plants. Here are five key takeaways to consider:

  1. Consider the Unique Light Requirements of Your Respective Plant – plants have varying light needs. Some plants require high light intensities, while others thrive in low light conditions. It’s essential to research each plant’s specific light requirements to provide the right amount of light to grow and thrive.
  2. Choose the Appropriate Light Spectrum – plants primarily use the light spectrum’s blue (400-500 nm) and red (600-700 nm) parts for photosynthesis. Blue light primarily serves the growth of leaves and stems, while red light helps flowering and fruit production. I recommend full-spectrum grow lights as they mimic natural sunlight and provide a balanced spectrum.
  3. Carefully Manage Light Intensity & Length – the amount of time a plant should be exposed to artificial light will vary significantly based on plant type. Again, it’s essential to research your respective plant’s preferences before firing up the grow lights. The intensity of the lights is equally crucial – too strong, and you’ll scorch the foliage, and too weak won’t be sufficient to support growth.
  4. Always Monitor and Adjust Temperature – some types of grow lights can get incredibly warm underneath, which can be an issue for some types of plants. LED lights tend to be cooler and are my preferred choice for indoor growing.
  5. Never Set and Forget Artificial Lights – from experience, results aren’t always consistent when nurturing plants under grow lights. It’s prudent to observe your plants’ overall health and development daily and weekly and adjust light intensity and duration as needed.

Why Plants Need Light to Grow

A small green plant growing under artificial light

Unlike humans, most plants don’t eat solid materials for energy. There’s no munching on some chips or nibbling on a chocolate bar. Instead, plants use the sun’s energy to convert water and carbon dioxide into carbohydrates. This process is known as photosynthesis.

If plants don’t receive enough light, they will become stunted and experience an overall decline in health. If you’ve ever placed a plant in a dark room, you know what we’re discussing.

The wavelength of light relates to the color that humans perceive. Plants absorb light between 400-700 nm for photosynthesis. Therefore, this range of light is known as photosynthetic active radiation (PAR). However, plants absorb blue light (400-500 nm) and red light (600-700 nm) the best.

Plants will absorb both red and blue light throughout their lives, and a balance of both types produces healthy plants. That said, the light types can affect the plant’s processes.

Blue light helps form chlorophyll, so it’s vital for the early vegetative stages. Red light, especially far-red light (700-850 nm), can help induce flowering and fruit set in plants.

How Effective is Artificial Light for Indoor Houseplants?

An indoor greenhouse filled with plants under rows of artificial light

Artificial light can be very effective for indoor houseplants! Of course, all light is not created equal. Just like you may need to move your houseplant around before you find the proper natural light, you may need to adjust your grow light to find a setup that makes your plant happy.

When you’re searching for a light, you need to be concerned about two main factors: intensity and spectrum.

The intensity refers to the brightness of a light and is measured in lumens.

It’s important to note that how you use the lights also impacts their effectiveness. Two factors to consider are the distance between the light and the plant and the number of hours the lights are on.

Even if you’re using a powerful light, placing it too far away from a plant will lead to weak plants. Not having a light on for enough hours will also lead to problems.

While light distance/intensity and the number of hours the light is on are both important, don’t fall into the trap of thinking one can compensate for the other. For example, you cannot use a high-intensity light for five hours instead of a low-intensity light for ten hours.

What Types of Plants Are Conducive to Artificial Lights?

A variety of small and large plants growing under artificial light indoors

Many types and sizes of plants can thrive with artificial lights. However, different plants will do best with different kinds of light, hours of light, and distances between the light and the plant.

Here’s a quick guide about artificial lights for commonly-grown houseplants.

Seedlings require large amounts of blue light to promote vegetative growth. The light should be just a few inches above the plants to discourage plants from stretchy to reach the light. Aim for twelve to fourteen hours of light each day.

Vegetative houseplants like pothos and monsteras benefit from artificial grow light with both red and blue wavelengths. Place the light one to five feet away from the plant, depending on the plant’s specific light needs. Keep the light on for six to twelve hours each day.

When using selecting and placing a light, consider the plant’s ideal light. For example, ZZ plants prefer low to medium indirect light, so you’d want to select a medium-intensity light and place it two to three feet away from the plant. Alternatively, you can use a higher-intensity light and place the light five to six feet away.

Flowering houseplants also benefit from a balanced light. However, you can switch to light with far-red wavelengths to induce flowering in the spring. When you do this, you still want to include some blue light to keep your plant healthy. Keep the light one to five feet away from the plant and keep it on for six to twelve hours each day.

Two houseplants next to an artificial light source in a very dark room

While many plants can be grown with artificial light, some perform better than others. The following houseplants typically thrive when grown with artificial light:

  1. African Violet (Saintpaulia): These small flowering plants will happily bloom continuously under fluorescent lights.
  2. Aglaonema (Chinese Evergreen): There are many varieties of Aglaonema with diverse leaf patterns and colors, all of which do well in artificial light.
  3. Boston Fern (Nephrolepis exaltata): It prefers bright, indirect light but can adapt to artificial lighting conditions if given enough moisture.
  4. Cast Iron Plant (Aspidistra elatior): As the name suggests, it’s a hardy plant that can survive in various conditions, including low artificial light.
  5. Dracaena: Several species of Dracaena are suitable for indoor settings, and they generally adapt well to artificial lighting.
  6. Fittonia (Nerve Plant): Recognizable by its veined leaves, Fittonia prefers indirect light and can be grown under fluorescent lights.
  7. Lucky Bamboo (Dracaena sanderiana): It can grow in water and soil and is tolerant of artificial lighting conditions.
  8. Maidenhair Fern (Adiantum): Delicate and feathery, Maidenhair ferns can thrive under fluorescent lighting if they’re kept humid and away from drafts.
  9. Peace Lily (Spathiphyllum): This plant is known for its glossy leaves and white spathes. It can flourish in low to medium artificial light.
  10. Philodendron: virtually all types of philodendrons can thrive under artificial light. They come in a variety of leaf shapes and sizes.
  11. Pothos (Epipremnum aureum): A trailing plant with heart-shaped leaves, pothos is adaptable to various lighting conditions.
  12. Rex Begonia: With its striking and colorful foliage, Rex Begonia can be a stunning addition to spaces with artificial lighting.
  13. Snake Plant (Sansevieria): Known for its upright, sword-like leaves, it’s one of the easiest plants to care for and can tolerate various light conditions.
  14. Spider Plant (Chlorophytum comosum): Recognized for its arching green and white variegated leaves, it is easy to grow under artificial light.
  15. ZZ Plant (Zamioculcas zamiifolia): With glossy, dark green leaves, ZZ plants are durable and thrive in low to medium light.

Plants That Prefer Sunlight

The truth is, any plant can be grown with artificial light. However, plants requiring lots of direct sunlight can be tricky. These plants can thrive under grow lights, but you’ll need to use high-quality lights that produce bright light.

Larger, more mature houseplants (typically over 4’ tall) can also be challenging to grow with artificial light since they require a lot of light.

Fiddle Leaf Fig plants and Meyer Lemon, from experience, have proved particularly difficult to grow successfully under artificial lights for reference. 

What are the Main Types of Artificial Grow Lights Suitable for Houseplants?

Large grow lights hang from a ceiling emitting purple colored light

When you start looking at grow lights, you easily become overwhelmed. Not only do you have to be concerned about lumens and spectrum, but you must also decide which type of artificial light you want. To simplify it, we’ve included information, pros, and cons about the main types of artificial grow lights.

Fluorescent Lights / CFL / HO

Fluorescent lights produce light when an electrical current passes through mercury vapor. This type of light is available in normal fluorescent tubes and compact fluorescent lights (CFL). CFLs pack more light into a smaller package. Some types of fluorescent lights are known as high-output (HO).

When looking at fluorescent lights, you’ll want to check the lumens and the spectrum.

While some fluorescent lights are labeled as grow lights, it’s also OK to use a generic fluorescent light. If you don’t see the spectrum listed on the light, you can look for a light labeled “cool white.” These lights contain a spectrum that is great for vegetative plants.

Pros:

  • Inexpensive
  • Available in a wide variety of sizes
  • Doesn’t produce much heat

Cons:

  • Contains the heavy metal mercury
  • Less energy-efficient than LEDs

LED Lights

LED lights are perhaps the best grow lights for the home grower. They’re not too expensive and are more energy-efficient than fluorescent lights. Each diode can emit a different wavelength of light, so multiple diodes can be combined to create just the spectrum you’re looking for.

Some LED lights are even able to turn certain diodes on and off. That means you can start with blue light during vegetative growth and then phase in more red light as your plant begins to flower.

Pros:

  • Last a very long time
  • Energy efficient
  • Low heat output
  • Available in a wide range of spectrums

Cons:

  • High upfront cost

Incandescent Lights

Fluorescent or LED lights have largely replaced incandescent lights. However, they are still available if you seek them out.

One key thing to know about incandescent lights is that they produce a lot of heat. Therefore, you should avoid placing these lights too close to your plant.

Pros:

  • Inexpensive
  • Emit red light

Cons:

  • Produce a large amount of heat

Halogen Lights

Halogen lights are not the best choice for growing plants, but they can be used in a pinch. Many types of halogen lights emit a full spectrum of light that is similar to sunlight.

Pros:

  • Inexpensive
  • No mercury

Cons:

  • Produce lots of heat

Metal Halide Lights

Metal halide (MH) lights are a great choice if you’re growing leafy plants without any flowers. These lights are similar to incandescent ones since they produce light by passing an electric current through mercury and a metal halide gas. However, they are more efficient and high-quality.

One of the most significant standout features of MH lights is their high intensity. These lights can produce some serious lumens, so you can use one elevated light for multiple plants.

Pros:

  • High-intensity output
  • Runs cool

Cons:

  • Expensive

Tips on Using Artificial Lights for Houseplants at Home

Two small succulent plants growing under a grow lamp in a very dark room

As we mentioned above, there’s no one size fits all answer for using artificial lights for houseplants. You’ll need to consider your plant’s needs and go from there. With that said, thinking about the following will get you off to a good start.

Determining How Much Light You Need

When it comes time to select lights, you’ll need to look at the light requirements of your plants. Plants that require low light won’t need to receive as much light as plants that require direct light.

However, you can use the same light for both plants that require bright and low light. The key is moving the light away from plants that require low light and closer to plants that require bright light.

Setting Up Artificial Lights

As we’ve mentioned above, the distance between your artificial light and your plant depends on the light’s intensity and light needs.

Positioning a light directly above a plant is best to encourage straight, upward growth.

Determining How Long to Leave Your Lights On

A thin light bar illuminates several green houseplants

Let’s clarify: you should not leave your lights on for 24 hours. Just like plants need sunlight, they also require periods of darkness. The hours of darkness, rather than the hours of light, are responsible for triggering plant processes such as entering dormancy and producing flowerings.                                    

When you’re determining how long to leave your lights on, you’ll need to consider the following factors.

  • Plant preferences: Look to see how much light your plant requires. If it requires 10 hours of indirect light, leave your light on for 10 hours.
  • Time of year: When you’re using artificial light on long-lived houseplants, you want to mimic nature. That means decreasing the amount of light in the winter and increasing the amount in the summer.

Growing Houseplants with Artificial Light FAQs: 

Can houseplants live on artificial light?

Artificial light can be adequate for indoor houseplants. The trick is to balance the intensity and type of light relative to the inherent needs of the plant you want to grow and nurture at home. As close as you can get to replicating the type and duration of light your houseplant would naturally receive in the wild will give your houseplant the best opportunity to thrive.

How do you grow indoor plants with artificial light?

Plants grown from seed will typically need longer light exposure durations than more mature plants. Aim to place your artificial light source overhead to encourage vertical growth and adjust the distance between the lamp and foliage as the plant matures.

What is the best artificial light for indoor plants?

For most indoor houseplants, the best option is full-spectrum LED grow lights. These artificial lights last a long time, are energy efficient, and produce a low heat output.

What color LED light is best for plants?

Plants will absorb both red and blue light throughout their lives, and a balance of both types produces healthy plants. That said, the light types can affect the plant’s processes. Blue light helps form chlorophyll, so it’s essential for the early vegetative stages. Red light, especially far-red light (700-850 nm), can help induce flowering and fruit set in plants.

Can I use grow light at night?

Houseplants need a natural daily cycle of darkness to rest and recuperate, so it’s recommended only to use your artificial grow lights during the day to mimic a natural day/night cycle.

Wrapping Up

The most important thing to remember about growing houseplants with artificial light is that it is possible! While it’s easy to get wrapped up in all the terminology and types of light, don’t be intimidated by using grow lights. By implementing artificial light, you can add plants to your home you would otherwise be unable to grow.

Contributing Editor | briana@petalrepublic.com | Full Bio

Briana holds a B.S. in Plant Sciences from Penn State University. She manages a small market garden where she grows vegetables and herbs. She also enjoys growing flowers and houseplants at home.

Spread the love

Leave a Reply

Your email address will not be published. Required fields are marked *