How Infrared Light Affects Plant Growth

Infrared light (or infrared radiation) is something we can’t see. Instead, we feel this radiant energy as heat. About half of all light energy that reaches the earth is infrared light and although it is invisible to the human eye, it has an obvious effect on plant growth. Here are a few reasons why infrared is a crucial part of the spectrum in our LED grow lights. 


  • Infrared plays a major part in what is known as The Emerson Effect.  In the late 1950s, American scientist Robert Emerson discovered that infrared light boosts photosynthesis when combined with other wavelengths. Photosynthesis is the process in which light energy is converted into chemical energy within a plant, allowing it to grow and produce. In other words, it is essential, and as Emerson found, the process is at its most efficient when infrared is present.   

  • In keeping with the discussion on photosynthesis, research shows that infrared light helps a plant bloom in its initial stages. This is due to the presence of phytochromes, a type of photoreceptor within a plant. Phytochromes help regulate the processes that are key to plant development i.e. leaf expansion, stem growth, and blooming, and it has been found that IR light plays a big part in stimulating that growth all year round. Exposure to this type of light makes a plant think that it is experiencing the same amount of light that it would receive during its normal growing season; this means plants in a grow room under LED lights can bloom and grow at any time of year. 
  • In a more general sense, plants react to infrared light by growing larger, which is manifested in bigger leaves to capture more light and stronger branching. Infrared is also known to boost the number of bud and flower sites on the plant, while other research confirms that this type of light increases certain antioxidants in the plant, and this means enhanced aroma and flavour. 

Just a few examples of why infrared light is so important in a plant’s development and growth. Of course, plants need the full spectrum of light to grow at their best. This further highlights the need for grow lights that can deliver the spectrum in its entirety. Not all grow lights are created equal and certain lights suit certain situations - for our expert advice on what will best match your specific requirements, feel free to contact us by phone or email.