Can Grow Lights Burn Plants

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Plants need light to grow. Without enough light, the leaves of plants can get willowed. 

Plants should get as much natural light as possible. Some people use artificial growth light to ensure their plants get enough light. They can also show symptoms of being burnt. 

Now, can grow lights burn plants? 

While using grow lights on plants is a good idea, some people face the trouble of their plants being burned by light. 

The right light does not burn the plants. Along with lights, the growth light provides heat as well. If the environment gets too hot, the plants can burn.  

This article discusses the root of it and gives you insights about grow lights and plant growth. 

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Understanding Grow Lights and Plant Growth

Grow lights are artificial lighting settings for plants. The use is mostly seen on indoor plants. 

Grow lights are lighting systems that sustain plant growth within a building or greenhouse. Grow lights have a wide range of spectrum colors and lumen outputs. That makes it possible to meet the lighting requirements of a wide range of plant species. Gardeners rely on indoor grow lights to ensure indoor plants receive adequate lighting even when windows are covered.

The photons produced by grow lights promote photosynthesis. These electric-powered lights contribute to the development and growth of. 

The human eye can distinguish light sources with a wide range of wavelengths, as different colors are ideal for photosynthesis. For example, the harvest and flowering plants respond best to red light, while vegetative development is promoted by blue light.

How to Tell if Grow Lights Are Burning Plants

If your plant is getting grow light burns, early detection can save it. So, you must know the signs and symptoms of your plants getting light stress.  

The onset of symptoms should not be expected to be instant. Instead, light burn is a slow process that manifests after a plant has been exposed to light stress for several days or weeks. So first, let’s check out the symptoms of a light burn.

Faded Foliage

When your plant doesn’t get enough light, the leaves lose their color. The green color of your plant’s leaves comes from chlorophyll. It is extremely difficult for plants to produce chlorophyll in too much light. Chlorophyll production requires a low-light environment.

Light is crucial for photosynthesis. Plants are unable to produce food and energy without photosynthesis. Thus their growth and development could be improved. But for certain plants, too much light can hamper photosynthesis

Yellow Leaves

Light burn shows mostly in the form of yellowing leaves.

The plant’s once-green leaves have begun to turn yellow. This affects the upper leaves first and works its way down the plant. Take notice if you see this symptom.

Green Veins

Light burn causes a yellowing of the leaves, but the veins keep their original color. This means that only some of the leaves will become yellow.

 Faded Flower Buds

Light burn can also be detected by looking at the color of the plant’s buds, if it has any. They stand out due to their bright white hue.

Hard Leaves

In case of a light burn, there are chances that the leaves will not turn yellow and fall just yet. Rather, the leaves become difficult to remove. Another problem, such as a lack of nutrients, could be to blame if the foliage leaves begin to fall after they change color.

Upward Facing Leaves

This symptom is rare. Some plants might not exhibit this symptom, or you might not notice it immediately. The leaves curl upwards, a symptom of light burn on the plant.

The Impact of Excessive Light Exposure on Plants

The impact of excessive light exposure on plants depends on two things: light intensity and light duration.

Light intensity is the amount of light shining on a given surface, measured in foot candles or Lux. And the light duration is the length of time the plant is exposed to light daily.

These are all distinct ideas that have unique effects on plant development. The intensity of the light is the primary factor to keep in mind. Let’s evaluate the factors one by one. 

Light Intensity 

High-intensity lighting causes plants to convert some of the light energy into thermal energy. To counteract this heat, your plant will likely use part of its liquid resources for evaporation.

This can eventually cause the plant to run out of water, which would be needed for functions like photosynthesis. 

The plant has a risk of damage by heat if its heat dissipation capacity is depleted. If the quantity of heat generated exceeds its heat dissipation capacity, the plant can also be at risk. The leaves may turn yellow or brown, the margins and tips may turn crispy, or the leaves may curl and fall.

Intense light could also dry up the soil the plant uses as a water source, hastening the rate at which the plant dries out. In addition, light has several negative effects on plants, and different species have different tolerance levels for bright illumination.

Light Duration

Many indoor plants can grow without light. You can leave your plants without light for a while without worrying much. But too much exposure to light can harm plants.

Excessive light exposure can negatively impact many plants’ development cycle and flowering potential. Plants have critical metabolic processes that occur at night. Therefore, they can grow quicker at night.

Insufficient darkness throughout the day prevents some plants from entering critical growth or flowering periods. Therefore, the plants in question are photoperiodic.

To flower, short-day plants need several weeks of nighttime temperatures below freezing. Short-night plants need light exposure to flowers. But excessive light can harm the quality of the flowers of the plants like many common herbs and vegetables.

Balancing Light Intensity and Plant Health

Balancing the intensity of light is necessary for the growth and health of the plant. The most common way to prevent the light burn from occurring is to lessen the intensity of the lighting and move the source further away from the plants.

You can apply several strategies to balance light intensity and plant health. Some are:

1. Light Fixture Adjustment

Relocating the light source far from the plants is the best option. However, once you discover the signs, you should do that promptly if you have the room and ability.

It is more complex than it sounds. You know you need to increase the distance between the fixture and the plants; however, do you understand how much more space you need? The ramifications of this are unclear.

The optimal yield of any plant requires a specific range of flux. Therefore, it’s essential to identify your plant’s minimal and maximum flux needs to determine how much light your plant needs.

2. Get Your Lights High Up 

Don’t get too close to your plants with any heat source. Keeping the lights at a safe distance from your plants is important. This is applicable for even LED lights with lower temperature output.

Hang your plants at the height recommended by the manufacturer. Find out the optimal height for hanging your grow lights in our related post. Keep your plants at least twelve inches from hot lamps, such as HPS or MH. 

Although heat and closeness can help during this phase, they do not negate the need for a dimmer light source, which is ideal for germination.

3. Install Automation

Hook up temperature sensors and light timers to your system so that the lights dim or turn on at the times you choose and the air conditioning turns on when the temperature rises above your predetermined limit.

Turning lights during the daytime is a waste in places with long days. Instead, switch your grow lights to run at night. While most grow lights perform best during the day, there are exceptions.

You will not need to worry about heat-stressed or burned plants if you utilize some simple automation and common sense. The most important thing is to maintain a close check on your plants at all times so that you can catch any problems early and take care of them.


Can LED Grow Lights Cause Fire?

LED grow lights are very unlikely to cause a fire. The plants are safe under them.

Can Plants Burn from LED Grow Lights?

 LED bulbs generate far less thermal energy. LED lights produce less heat, but plants will still burn if they are too close.

Can Plants Get Too Much Grow Light?

 You can only give your plants a little light. But the heat it generates sometimes is too much for them.

How Far Should LED Grow Lights Be from Plants?

The distances between plants to the light can be anywhere from as 2 inches and as much as 2 feet, according to the kind of light and the kind of plant you’re cultivating.

Can I leave LED Grow lights on all night?

No plants need more than 14 hours of light. So, you should not leave LED grow lights on all night.


Usually, the heat from grow lights kills plants, not the light. But too much exposure to grow light can cause severe damage to your plant. Knowing the answer to “Can grow lights burn plants? “ will help you prepare the right light setup for your plant. 

However, you should watch the plants and maintain a safe distance between the leaves and the lights. That way, you reduce the likelihood of grow lights burning your plants and easily avoid it.

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Jack Daniel

I am Jack Daniel, and I have been gardening for more than 20 years now. I believe that with my years of experience, I can help you with backyard ideas and backyard product reviews. So, with the motto to help anyone facing gardening issues or wanting tips on enhancing the beauty of their backyards, I have created Backyard Muse. So, before anything else, I want to welcome you warmly to my site.


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