Lettuce is popular vegetables people like to eat year around. But growing lettuce during all seasons is not possible. But many growers are using LED lights to grow different crops year-round. The obvious question is can lettuce grow under LED lights so that we grow lettuce year-round too?
Here we will address the question and explain the scientific reasons and advantages of using led lights for growing LED lights.
Can lettuce grow under LED lights?
The answer is yes you can grow lettuce under LED lights. Many growers all around the world are growing lettuce under LED lights. Especially hydroponic growers are taking advantage of LED technology to grow lettuce indoors.
The hydroponic market is already more than a 2 billion dollar industry in the USA. Lettuce is one of the widely grown vegetables. The majority of them use LEDs as a source of light to grow crops.
The science behind growing under LED lights
The answer is definitely yes when it comes to using LED lights for growing lettuce but why? Here we are going to look at the different scientific reasons why LED lights are a good source alternative source of light.
Why do plants need light to grow?
The reason is photosynthesis.
Photosynthesis is the process that converts light into glucose which is like fuel for the crop. Just like the sun, LED lights also provide the light required to perform photosynthesis.
However, it is the combination of the red and blue light spectrum that supports photosynthesis.
Plants require a light spectrum between 400 nm to 700 nm to sustain photosynthesis.
- The blue light should be between 400-500 nm
- The red light should be between 600-700 nm
Also, growers adjust light intensity during different growth stages to sustain the optimum growth of the lettuce crop.
It is the basic science behind growing lettuce under LED lights.
Advantages of Growing under Led lights
Sun is a great and free source of light but LED lights have some advantages that the sun cannot beat.
During gloomy weather, getting appropriate sunlight is not possible. But with LED you can constantly provide 14-16 hours of light required for growing lettuce. Not just constant light but you can provide light with same intensity too.
Growing any vegetable irrespective of the external weather is a big advantage of LED lights. You can grow lettuce almost year around.
It is due to the introduction of LED lights, growers can now efficiently use hydroponic or aeroponic systems. These growing methods are gaining popularity in places where soil farming is hard.
When we use the sun as a source of light, we have to position the whole setup as per the direction of the sunlight. With limited space and resources, sometimes it is hard to adjust to the sunlight.
But with LED light, you do not rely on the direction of the sun. You are free to set up your grow set up wherever you want and adjust the LED light according to it.
Not just the direction you adjust the height of the light to provide the best possible chance for plants to efficiently absorb the light.
Light Intensity Control
Another big advantage of using LED lights is that you can control the intensity of light as per the crop’s requirement.
Lettuce does not require the same intensity of light for 12-16 hours. It has to be well-balanced.
With LED lights you can control which type of light you want to provide. Because when you use full spectrum LED light it has white, blue, and red light.
Too much intensity of light might cause light stress and may cause browning of leaves. And if the light intensity is too low the plant may remain undernourished.
So you have to provide the right amount of light, at the right time which is possible when you are using LED with a controller.
When you use the sun or another source of light, they also produce heat. And crop like lettuce is quite sensitive to heat.
To avoid heat stress you need to make sure that system of the whole grow system remains under threshold levels.
For growing lettuce you need to maintain 60 to 65 °F.
LED doesn’t produce that much heat. Also if you use LED lights with a heat dissipation unit, you can maintain a constant temperature of the hydroponic system or any other grow system.
When we compare other lights like halide and fluorescent lights, LEDs consume less power. When you are running a bigger hydroponic set up the cost of lights can be a huge expense. For a crop like lettuce, you will be using lights 12-16 hours per day. It will definitely burn a hole in your pocket if you are using other forms of light.
But by using LED lights you can reduce your cost up to 70 percent.
To give you an example, if you are using a 60 W incandescent light, according to DOE, the annual cost of using it is $4.80. But using a 60 W LED will cost you only $1.
Moreover with the same wattage LED lights burn brighter and produce less light. It is another big advantage to have LED lights to grow lettuce.
It is a known fact that LED lights last much longer than other lights when you are looking to use artificial lights for growing crops indoors.
When you compare the lifespan of LEDs with Halide grow lights, LEDs last almost 10 times longer than Halides.
Also, LEDs last 50 to 100 times longer compared to incandescent lights.
And when you are using them for systems like hydroponic grow systems, you have to consider maintenance costs as well.
LED lights require less maintenance compared to other lights.
Looking at the so many advantages of using LED gives you a definite answer that yes lettuce can grow under LED lights. It is only a matter of having the right knowledge and right equipment to grow lettuce.