How close should LED grow lights be to plants? This is important because placing your grow lights correctly promotes productive indoor plant growth.
So is this distance standard for all plant types and all growth stages? Or how do you determine the right distance?
This article explains how far you should place LED grow lights and the factors determining how far you should.
Why Does LED Grow Light Distance Matter?
Without a doubt, it’s essential to have the optimum distance of LED grow lights from the plants for two main reasons:
One is to ensure the delivery of the right light intensity. With the right distance, it provides the required amount of light, which helps a plant grow healthy.
So it would be best to position the lights to provide adequate photosynthetic active radiation needed for photosynthesis.
Second, to avoid the adverse effects of incorrect grow lights distance. Because if the light is too close, it will scorch the plants. And if you place the lights too far from the plants, it will cause irregular growth.
Thus, the plant will present symptoms of distress, such as stunted growth or a white or yellow discoloration known as bleaching. Also, you’ll notice the leaves pointing upwards or the plants growing facing toward the light as they struggle to get enough of it.
How Far Should LED Lights Be From Plants?
The distance between the lights and the plants can generally range between 2 to 24 inches. See, different plants have varying light needs.
So to position your plants well, you can start at 18 to 24 inches between the plants’ canopy and LED lights. Then, observe the plant and vary the distance until you find the one that suits your plant best.
Remember that several other factors determine how far you’ll place the lights, as we’ll see below.
How Far Should LED Lights Be From Seedlings?
Now the seedling stage is a very tender and vulnerable one. That’s because it’s prone to excessive water loss.
Therefore, keeping the LED grow lights a little higher up from your plant’s canopy is best to ensure the soil does not dry up. Also, it helps reduce transpiration levels.
During this stage, the plant also requires less light. And here, the beam size and wattage will determine the LED grow light distance for the seedlings.
Therefore, place the lights 25 to 36 inches above the soil. Otherwise, exposing the seedlings to too much light will hinder a fast growth rate. Worse, it could damage the plant altogether.
Factors That Influence Plant Placement Distance
Plant Type
Different plants have different light intensity requirements. For example, decorative indoor plants, such as snake plants, need less than 4 micromoles per square meter per day of DLI (daily light integral).
On the other hand, leafy plants like lettuce and herbs need four to five times more daylight, while other plants, such as tomatoes, require even more light.
(Caption: Young tomato plant with LED light closer to it)
Beam Width
Regarding beam width, manufacturers design LED lights to provide concentrated or dispersed light emissions. Thus, you may notice that some lights have exposed LED chips.
These can emit light in all directions. Also, they cover a huge area. But as great as such lights sound, they have a caveat. Generally, they tend to have lower light intensity.
On the other hand, some LED lights have light-concentrated lenses. These concentrate an array of light on a specific area. These have high light intensity but cover a smaller area of the plants.
As a rule of thumb, place a more concentrated LED light away and one with a wider beam closer to the plants.
Wattage
Now high-wattage LED lights produce more light. Therefore, placing such lights further away from your plants is reasonable. On the other hand, it’s safe to position the low-wattage LEDs closer to the plants.
Therefore, check the wattage of your LED lights to determine the appropriate distance to place them from the plants.
Plant Maturity Stage
At different stages of maturity, plants require varying amounts of light. The followings are some plant stages and their LED light placement needs:
- Seedlings: Just as babies eat less, seedlings require less light. Thus, it would be best if you placed the lights further away from the plants.
(Caption: Seedlings growing under LED grow lights)
- Vegetative stage: During this stage, the plant requires intense light. One reason is that the plant is growing rapidly. Thus, it needs lots of light to keep up with its photosynthetic process needs. Also, at this stage, the plant rapidly strengthens its stem and root systems and needs lots of energy. So you want to place the lights closer to the canopy.
- Flowering: The flowering stage is the final one for plant growth. And at this point, the plant develops flowers and forms fruits and requires less light. Thus, it’s important that you raise the LED lights higher throughout the plant’s transition from the vegetative to the blooming phase.
FAQs
How Close Can LED Lights Be to Plants?
Generally, LED lights don’t emit much heat, so you’ll find that you can place the plants much closer than you would with other types of light.
Thus, for some plants, you can keep the lights as close as two inches. However, it would be best if you kept closely monitorsigns of light burns, such as bleaching.
How Far Away Can LED Lights Be From House Plants?
Generally, house plants don’t require much light. Therefore, when using LED lights, you can place them relatively further away from these plants, but not too far.
An ideal distance would be 12 to 20 inches away for a bulb with a wattage of 200W. But keep a close eye on the plant to see how it reacts.
And if the plant shows any signs of distress, such as non-uniform growth or bleaching, then adjust the distance.
What Is the Proper Placement of Grow Lights?
In simple terms, it favors healthy growth. That means not too close to cause bleaching and not too far so that the plants suffer stunted growth.
Generally, you can place the lights between 2 to 24 inches from the plants’ canopy. But remember factors such as the type of plants, what stage of growth the plants are, and the LED’s wattage and beam size influence how close you can place the lights.
Conclusion
So how close should LED grow lights be to plants? As we’ve learned, it depends on the type of plant, the stage of growth the plants are at, wattage, beam width, and growth method.
And this distance matters for plant health and productivity. So now you know the distance to leave between your plants and grow lights for optimum plant growth and production.