Everything You Need to Know About Grow Lamps for Houseplants

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 that plants need. But don’t worry, you can use artificial lights instead and with a few well-followed guidelines your houseplants will thrive just fine. Here we’re going to take you 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 up, and the most common problems to mitigate. 

Growing Houseplants With Artificial Light – The Essentials

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 will also need to match the light’s position and hours to meet your plant’s needs and avoid scorching the plants.


Why Plants Need Light to Grow

Why Plants Need Light to Grow

Unlike humans, most plants don’t eat solid material for energy. There’s no munching on some chips or nibbling on a chocolate bar. Rather, 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 talking about.

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. With that said, the types of light can affect the plant’s processes.

Blue light helps form chlorophyll, so it’s especially important 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?

How Effective is Artificial Light for Indoor Houseplants

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 how effective they are. Two factors to consider are the distance between the light and the plant as well as 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?

What Types of Plants are Conducive to Artificial Lights

Many types and sizes of plants can thrive with artificial lights. However, different plants will do best with different types of lights, 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 over to a light that includes 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.

Plants That Thrive Under Artificial Light

Plants That Thrive Under Artificial Light

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

Plants That Prefer Sunlight

The truth is, any plant can be grown with artificial light. However, plants that require lots of direct sunlight can be a bit 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 a bit difficult to grow with artificial light since they require a large amount 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?

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

When you start looking at grow lights, it’s easy to become overwhelmed. Not only do you have to be concerned about lumens and spectrum, but you also need to decide which type of artificial light you want. To make it a little easier, 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 you’re looking at fluorescent lights, you’ll want to check the lumens as well as the spectrum.

While some fluorescent lights are labeled as grow lights, it’s also fine 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

Incandescent lights have largely been replaced by fluorescent or LED lights. However, they are still available if you seek them out.

One key thing to know about incandescent lights is that they produce a good amount of heat. Therefore, you should be mindful of 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

If you’re growing leafy plants without any flowers, metal halide (MH) lights are a great choice. These lights are somewhat similar to incandescent lights 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 biggest 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

Tips on Using Artificial Lights for Houseplants at Home

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 specific 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 to move the light further 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 as well as your plant’s light needs.

It’s best to position a light directly above a plant to encourage straight, upward growth.

Determining How Long to Leave Your Lights On

Determining How Long to Leave Your Lights On

Let’s get one thing clear: you should not leave your lights on for 24 hours. Just like plants need light, 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.

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.


Growing Houseplants with Artificial Light FAQ: 

Artificial light can be very effective for indoor houseplants. The trick is to balance the intensity and type of light relative to the inherent needs of the plant you’re looking 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.

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

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

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

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


Author

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.

Comments are closed.

;