How far should LED grow lights be from plants?

Led grow lights for plants are now becoming very popular because they allow you to grow plants indoors even during winter and extremely cold weather. The led grow light mimics the sun in providing heat and photosynthesis so plants can thrive and even flower and bear fruits. If you already have best led grow light but don’t’ know where to place it, this article will help you get started.

To answer the question of how far should LED grow lights be from the plants; there is actually no direct answer to that. First, you need to know the different types of grow lights, because there are several types out there. These grow lights have different power ratings and require different distances to serve its purpose. The distance also depends on the type of plants you are growing and in what stage of growth they in. Seedlings light requirement is different from that of a mature plant. And these are just a few of the things you have to consider.

Kinds of led grow lights

  • Violet-blue light – these are of 400-520 nanometer range. Best for chlorophyll absorption, encouraging photosynthesis and growth.
  • Red l
    – has a 610-720 spectrum range. This is used for budding and encourages flowering.

Types of grow lights

  • Incandescent grow bulbs– this type of grow lights has a high heat output but with low efficiency. It has a lifespan of 700 hours.
  • Fluorescent grow lights– this type of grow light has low heat output and is used for growing. It has an average lifespan of 10,000 hours.
  • LED grow lights– this is the latest technology for grow lights. The low-heat output and the right spectrum of light range make it very ideal. The color and low heat optimize growth for your plants. By far this is the most efficient and effective grow lights with an average of 50,000 hours.
  • High-Intensity Discharge (HID) – this bulb is commonly used by commercial growers because of the high-intensity output. It can cover a broader space and deliver a bigger output.
  • Metal Halide (MH) – this grow light like HID produces high-intensity lights and are also used by commercial growers.

Proper LED grow light position

Now that you know the type of lights, you can now determine where is the best light placement for your LED grow lights. Technically the best placement would be to put it hanging or over the plant beds. This will mimic the sun shining from on top. exposing all the plant leaves and the sides of the plants that would benefit from the light. As we have mentioned above LED grow lights are the most ideal in growing plants because of its low-level heat output. That being said, it is best to get these grow lights for your different planting needs.

Generally, because LED and fluorescent have lower heat output they can be placed overhead of about 12 and 6 inches from the plant. For those who are using incandescent grow lights the light should be about 24 inches above the plants. Later we will give you a detailed reference of LED wattage and where to ideally place them.

Remember to monitor the growth of your plants because you need to keep adjusting the grow lights. The distance of the grow light must be maintained at all times. If you put the light too close it can stunt the growth of the plant. If you place it too high, you will risk stretching which is not good for some plants, especially if you are growing indoor plants.

Varying light requirement

You also have to keep in mind that the lighting requirement may vary according to the plant you are growing. You may need different grow lights at given times and maintain specific distances for different types of plants. You have to cross check the different characteristics of the plants you are growing and categorize them so it’s easier for you to group them together. This way you won’t be spending too much on numerous LED grow lights.

Vegetative plants during the growth stage will greatly benefit from LED grow lights. It encourages healthy growth cycle and produces green leaves. During the growth period, you can keep it under 24 hours of light mimicking that of summer days where there are longer days;  although the recommended light exposure at this stage is only 18 hours. When your plant transitions to the flowering stage you can switch the light exposure to 12 hours.

For flowering plants, a reduced light exposure will increase yield and size of the flowers. You can use a special LED flower booster. This stage usually lasts for about 8 weeks or so.

When cloning plants you need to use the right LED grow lights to encourage propagation. Mother plants must be 2 months old and require 18 hours of light. To grow clones you can use 240-watt and 450-watt lights with a 12-18 inches distance overhead.

Here is a detailed reference for different LED grow light power and recommended distance;

  • 240 Watt – 12 to 24 inches overhead. It covers 2-4 mature plants.
  • 450 Watt – 14-30 inches overhead. Can cover 4-8 mature plants. This grow light is also ideal for mother plants and cloning.
  • 600 Watt & 900 Watt – this high wattage LED grow light should be placed 16-36 inches overhead.

Advantage of LED grow lights

The LED grow lights emit less heat as compared to MH/HPS systems. That’s why it is commonly used by more people. It is also gaining popularity because it is also cost-efficient. With LED grow lights it is easy to control the temperature in your nursery.

These grow lights also eliminate the risk of plants getting burned. Rest assured that your plants will grow to your desired size or maintain its green leaves. If you notice yellowing or the tips of your plants drying out, this is a sure sign that the grow lights are too much for your plants. Try to adjust the distance of the light and see if the color of the leaves changes.

Using LED grow lights for plants also help maintain water evaporation at a minimum. The plants will not wilt under the light and the soil will also keep its moisture.

For plant growers, they know that darkness is part of the growth cycle. While sunshine helps in the photosynthesis of plant, at night or when it gets dark “respiration” happens and this is the time when plants use their energy to grow and flower. So keep a balance in your nursery and turn off your LED grow lights when necessary. Remember that vegetables and flowering plants require 12 to 16 hours of light. Equally, you need to provide darkness of about 8 hours for the plants to function normally.

If you are still unsure about how far your LED grow lights be from your plants it is best to contact the manufacturer or refer to the packaging. Usually, there will be a reference there on the proper distance depending on the wattage of the bulb.

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