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Cannabis Lighting: Understanding Light Distance

Updated: Jul 1, 2021

When cultivating cannabis, there are a lot of factors you must be aware of to ensure proper growth. One of the most important elements during every phase of your plant’s growth cycle is lighting. While lighting is crucial to any plant’s life, careful light regulation with your cannabis can do wonders for its potency and flower growth.

However, cannabis lighting is more than just keeping light on and off for certain hours of the day. Lighting comes down to frequency, strength, color, and even distance. Today, we’re focusing mainly on the effect that proper light distancing has on your cannabis plant, and why it’s so helpful for successful growth.

The Importance of Light Distance

During plant growth, lighting helps to nourish your cannabis, strengthening it to help it flourish correctly. Natural-grown plants simply rely on the light cycles of the sun to take care of them; cannabis plants, on the other hand, are a lot more complicated. The amount of light that they receive can directly correlate to the plant’s THC percentage and yield.

Because of this, growers often want to provide their plants with as much lighting as possible to help nourish growth and potency. While this is a good idea, in theory, too much light can also seriously damage your plants if you’re not careful. Having too strong of lights too close to your plants can result in light burn which will potentially ruin your crop by degrading cannabinoids and terpenes. If you begin to notice your plants’ leaves yellowing or wilting, this is usually a major sign that they’re getting heat damage from the lights, and that the distance must be adjusted.

Proper light distancing guarantees that your cannabis plants are still getting the right amount of nutrients, but that they aren’t getting over-exposed to light and damaged because of it. This requires you to find the perfect balance of distance and wattage during each stage of growth. Don’t worry, Luna Cultivation is here to help.

Ideal Distances For Your Cannabis Plants

Because every stage of the cannabis growth cycle is unique, you’re going to find that the light distances differ between stages as well. All of this depends on what your plant needs most during that stage, as well as what kind of lighting you’re using and its wattage. However, we can provide some general answers when it comes to ideal lighting distances per growing stage.


While your plants are just beginning to sprout, generally, we suggest having your grow lights around 2-3 feet above your plants, in your subcanopy. Allowing this kind of distance creates the perfect amount of nutrition without worrying about drying or heating your plants too much.

Of course, if you have lights with very high wattage, they will probably need to be placed even further than this to guarantee proper growth from your seedlings. This early in the life cycle of your cannabis plants, it’s important to treat them gently and with care; they don’t require nearly the amount of light as they will when they’re in the vegetative or flowering stage.


Speaking of the vegetative stage, it is during this time your plants are going to undergo the most growth. All of this extra growth requires more energy and more nutrients for your cannabis plants, so more intense lighting works best here. Again, just make sure the lighting isn’t too intense that your plants are being affected adversely.

For better photosynthesis, we suggest having your lights between 1-2 feet away from your plants during the vegetative stage. Having stronger lighting here will help aid in the growing process, ensuring that plant growth is just as you want it by the time it reaches the flowering stage. We cannot stress enough how crucial it is to keep a close eye on your plants during these harsher stages of lighting.


As you enter the flowering stage, the light distancing here is going to vary quite significantly. Growers will place lights anywhere from 1.5 feet to 3 feet away from their plants depending on what they want from their cannabis. Typically, if your plants have reached the growing size you’re satisfied with, you can safely distance your lights a bit further away. However, if you’re hoping for more growth, closer lighting can be beneficial during the flowering phase.

Keep in mind that it is during this stage that you see actual growth from your buds, rather than the stems and leaves themselves. Many farmers start their lights off closer to their plants as they finish off their growing, then slowly move lights further away to allow for the buds and flowers to thrive.

Light Distances Per Grow Lights

As we mentioned, different grow lights will require slightly different techniques and distances depending on their strengths.


Fluorescent lights don’t tend to be as strong as other lights like LEDs or HIDs, so you’re less likely to experience light burn. However, they’re also more difficult to control and have to be more closely monitored than other types of lights.

With their lower wattages, growers tend to place these lights 6 inches to 1 foot from their growing plants.


LED lights are most commonly used, as they’re easy to control and come in a variety of wattages. All of the above numbers that we stated during the life cycles apply to LED lights in particular.


HID lights are some of the strongest grow lights you can buy, containing thousands of watts. If you have lighting that strong, growers typically start by placing them between 20 and 26 inches away from the plants and then gradually moving them closer as vegetation occurs.

If you’re using HIDs, make sure to stay attentive to their effects on the plants, as well as their performance. These lights are so strong that they’re prone to breaking. If they do, replace them ASAP.

Perfecting Cannabis Light Distancing

All in all, finding the perfect lighting for your cannabis plants is going to take a bit of trial and error. Every plant acts differently, and all growers have their own techniques that influence the way that their cannabis is grown. That being said, as long as you’re paying close attention to the composition of your plants, their progress, and the heat coming from your lights, you should be all set to experience a successful cannabis yield.

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