How Far Should Grow Lights Be from Plants?

January 16, 2020 jake ovenden 0 Comment

This comes up as a common question for new and experienced gardeners as the ramifications can be catastrophic. If you have the light too close to your plants they will get burned and if you have the light too far away, the plants will stretch and be weak. However, there are many factors into how far away your LED grow lights need to be hung, so let’s look into them!

What is The Best LED Grow Light?

Before deciding the hanging height, you will need to find the most suitable light for your plants. This means what type of LED light you want and how many watts it uses. For deciding the most suitable LED grow light for your indoor garden or plants you will need to look at some key features of the light. The design and the heat dissipation play a big part in this choice. Would you like an LED Grow light panel or a group of LED grow light bulb? Once you have decided this you can begin to look at the light’s heat dissipation. For heat dissipation in LED grow lights you are looking at two different types. One form of LED grow lights attaches the LED chip to the light via thermal paste, PCB boards and grow lights that use ceramic attach the chip directly to the ceramic heat sink. Although both types of technology make LED grow lights more efficient than traditional grow lights the use of ceramic will guarantee a longer lifespan of the light. Due to the fact, there are fewer pieces surrounding the LED chip.

How Many Watts do You Need?

Depending on the size of your grow, there is an unofficial rule that is relatively followed by growers around the world. You want to be looking for around 20-40 watts per square foot. In order to find the minimum and maximum of your Grow light intensity range, you can divide the wattage of your bulb by 20 and 40. 

For example, if you have a 1000W LED Grow Light, the intensity range will be:

1000/20=50 and 1000/40=25

This is your intensity range if you have a 1000W grow light, you can light up between 25-50 square feet depending on your plants. Your plants' growth and health would need to be observed in order to find the best intensities, as this is just a range finder.

Do Different Stages Need Different Distances?

Yes, they do! Each different stage of growth requires different lighting needs and intensities. If your LED grow light is not dimmable, you will need to adjust the height and distance of your plant accordingly. However, it is important to remember if you would like to be more accurate you may need to contact your manufacturer to find out your LED chip’s power, beam angle, and lenses.

Seedling Stage

Seedlings require the least intensity from LED grow lights. This means you will need to keep them a further distance away from the grow light. Depending on the type of plant you have and the strength of your grow light, as a general rule seedlings need longer light exposure at a lower intensity.

Vegetative Stage

For the vegetative stage, the plants will be beginning to turn green and this is where a full spectrum daylight beam is the best option. The lighting spectrum can be similar to that of what was used for seedlings but with a higher intensity. This would mean moving your light a little closer to your plants. The best thing about using LED grow lights is that they have a low light infrared signature, meaning plants can be placed closer to them than other lights and they will not burn.

Flowering Stage

The flowering stage of a plant requires the highest intensity. However, plants need to slowly adapt their light intensity from the vegetative stage. You can do this by lowering the hanging height of the grow light slowly until you reach the manufacturer’s recommended height.

Conclusion for the Best distance For LED Grow Lights From Your Plants

The exact distance an LED grow light should be from your plants has too many factors in order for it to be simply defined. It would depend on the plants you are growing, the spectrum of your beam (mainly blue and red), the power of your lights and what phase your plants are growing. However, this blog can give you a general idea of what to look for and how to plan out finding out the best height for hanging your grow light. Good luck fellow gardeners!