The Truth About Indoor Plant Lighting: Is a Grow Light Necessary?

Written by Linus Li


Posted on June 08 2023


  1. I. Introduction
  2. II. Some Plants That Can Survive Without a Grow Light
  3. III. Challenges of Relying on Ambient Light
  4. IV. Symptoms of Insufficient Light
  5. V. Benefits of Using a Grow Light
  6. VI. Plants That Benefit the Most From Grow Lights
  7. VII. Key Factors to Consider When Choosing a Grow Light
  8. VIII. Conclusion

I. Introduction

Many common indoor plants can adapt to survive with only ambient household light, but optimal grow light is often required for plants to truly thrive indoors. Without the right quantity and spectrum of light, indoor plants will show telltale signs of light deficiency, like elongated stems, sparse foliage, and yellowing leaves, limiting their growth and aesthetic appeal. Specialized grow lights can be invaluable for keeping indoor plants healthy and avoiding issues.

II. Some Plants That Can Survive Without a Grow Light

While many indoor plants benefit from additional growth light, several species have adapted to survive with very low light levels. These plants can often tolerate the diffuse, indirect light that comes through windows in most indoor environments.

Some of the hardiest low-light plants include:

Snake plant

With thick succulent leaves, snake plants can go weeks without water and months without supplemental light. They are one of the easiest and most forgiving indoor plants.


Featuring variegated leaves and vines that can climb poles, pothos plants tolerate very low light and infrequent watering. Their ability to adapt makes them popular office plants.

ZZ plant

Low-maintenance ZZ plants are Zamioculcas zamiifolia, also known as the Zanzibar gem. These foliage plants can survive in deep shade conditions with infrequent watering. Their low growth habit makes them well-suited for tables and desks.

Spider plant

With long, straplike leaves and offshoots that produce baby plants, spider plants are well-adapted for lower-light environments. They do well placed in any corner that gets some natural light.

Overall, these and other durable indoor plants have traits that enable them to tolerate weak household light, surviving mainly through adaptation and slowing their growth rate. While superficial light intensity is low, sufficient photons still reach their leaves to carry out basic metabolic functions.


grow light


III. Challenges of Relying on Ambient Light

While many plants can eke out an existence using only ambient household light, they face considerable challenges that limit their health and growth potential.

Limited Light Intensity

Natural and artificial light levels in homes are typically quite low, ranging from 50 to 250 LUX. This provides barely enough photons for photosynthesis in low-light tolerant plants.

Inadequate Light Spectrum

Most household lamps emit a disproportionate amount of "warm" yellow and red wavelengths, lacking the "cool" blue spectrum that many plants require. This can impair plant functions.

Unpredictable Light Exposure

Indoor light conditions are changeable depending on weather, seasonal shifts, and obstructions. This makes it difficult for plants to establish a consistent photoperiod that supports optimal growth.

These issues mean that while plants survive under ambient light, they often appear etiolated with long stems and sparse foliage. Relying solely on household light limits their potential size, vigor, and aesthetic appeal. Specialized grow lights can help remedy these challenges by providing higher-intensity light in a customized spectrum with more controllable photoperiods.

IV. Symptoms of Insufficient Light

When indoor plants do not receive enough light to meet their photosynthetic demands, they exhibit telltale symptoms of light deficiency. The most common signs include:

  • Elongated stems: Plants stretch towards available light sources, producing long, leggy stems with widely spaced internodes.
  • Sparse foliage: Leaves are small and spaced far apart along the stem. Plants produce fewer overall leaves to minimize energy demands.
  • Yellowing leaves: Chlorophyll production declines, causing leaves to yellow, fade, or pale. Some lower leaves may drop prematurely.
  • Stunted growth: Plants remain small and fail to reach their typical size potential due to the limited resources provided by weak light. The growth rate slows dramatically.

These symptoms indicate that ambient light conditions are limiting the plant's photosynthesis and energy generation. The poor light environment constrains the plant's physical development. The use of targeted grow lights can help reverse or prevent these symptoms by boosting available photons and optimizing the light spectrum to match the plant's needs. This enables more robust, balanced growth and a healthier appearance.

V. Benefits of Using a Grow Light

Using a dedicated grow light can offer several key benefits for indoor plants compared to relying solely on ambient household lighting:

Stronger Light Intensity

Grow lights produce far higher light levels, from 300 to over 2,000 LUX, providing the photons needed for optimal photosynthesis and vigorous growth. This supports larger, fuller plants.

Customized Light Spectrum

Most grow lights emit light explicitly tuned to the absorptive range of chlorophyll, with a balanced proportion of blue, red, and other wavelengths that plants require. This promotes healthier foliage and flowering.

Consistent Light Exposure

Grow lights can be programmed to provide a set photoperiod tailored to a plant's needs. This regulates the light-dark cycle and helps establish reliable seasonal cues that mimic outdoor conditions.

Together, these advantages help indoor plants realize their maximum growth potential and thrive rather than just survive. Stronger light aids resource acquisition, while the customized spectrum supports key metabolic processes. The controlled photoperiod allows plants to establish natural rhythms that facilitate balanced development. As a result, indoor plants tend to become larger, bushier and exhibit more vibrant foliage under supplemental grow light.

In summary, using a dedicated grow light translates to healthier, hardier, and more aesthetically pleasing houseplants that more closely resemble their counterparts in nature.

VI. Plants That Benefit the Most From Grow Lights

While many indoor plants can benefit from supplemental grow lights, some species gain disproportionate advantages due to their specific light requirements. These "high-light" plants tend to benefit the most from targeted illumination:


As epiphytes with thick leaves, orchids typically need high light intensities upwards of 2,000 LUX. Grow lights can provide the strong photon flux densities required to sustain healthy blooming and prevent leaf drop.


Though low-light tolerant, many succulents like echeveria and aloe thrive under high light levels that grow lights enable. This supports compact growth, vivid colors and maximizes photosynthesis.

Peace lilies

While technically considered low-light plants, peace lilies often benefit significantly from intermediate to high-light conditions to promote healthy foliage and prolific blooming. Grow lights can satisfy their light needs.


Most ferns are classified as medium to high light plants, requiring 500 to 1500 LUX for optimal growth. The cool temperatures and high humidity they prefer indoors, combined with weak ambient light, often lead to poor growth without supplemental lighting.

In general, any plant classified as a "medium" or "high" light species stands to gain the most from grow lights that provide the higher intensities and tailored spectra needed to fully express their natural form indoors. For these light-loving plants, robust growth, lush foliage, and even flowering often depend on targeted supplemental illumination.


grow light


VII. Key Factors to Consider When Choosing a Grow Light

When shopping for the right grow light for your indoor plants, several factors should be considered to maximize effectiveness:

  • Light intensity: This is measured in lumens or lux and indicates how many photons the light will produce. Choose a light intensity appropriate for the specific light requirements of your plants.
  • Light spectrum: Look for lights that emit wavelengths tuned to chlorophyll absorption, especially blue and red bands. Some lights offer an adjustable spectrum to suit different plant groups.
  • Timers or photoperiod controls: Lights with built-in timers or photoperiod controls allow you to set the duration of light exposure, mimicking seasonal day length. This helps regulate plants' growth cycles.
  • Other considerations include:
  • Form factor: Choose between clip-on lights, desk lamps, or suspension fixtures depending on plant location and your aesthetic preferences.
  • Adjustability: Opt for lights with dimmers, angles, or height adjustments to customize intensity for different plants.
  • Efficiency: Consider the light output per watt to minimize energy usage. LED lights are the most efficient option.

Know more from our blog: LED Grow Lights: Can You Use Any Light Source?

VIII. Conclusion

With proper grow lights, indoor plants can truly flourish instead of merely surviving on ambient light. This supplemental illumination, providing higher intensities and customized spectra, enables most houseplants to reach their full potential, developing complete forms rather than the etiolated growth often resulting from ambient light alone.

For optimal results, plants benefit the most from grow lights tailored precisely to their specific intensity, spectrum, and duration needs. The right customized lighting strategy allows indoor plants to enrich living spaces by realizing their highest natural potential.

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