Cannabis Light Burn

Cannabis Light Burn
December 07, 2020

Light Burn Weed

Light is one of the essential factors in your cannabis growing process. However, too much light can be harmful and risk damage to your plant. It’s important to regulate the amount of light that your cannabis plant receives in order to prevent light burn or stress on the plant itself. Light burn is mainly a very common issue with growing indoors and can be caused from LED light burn. If your outdoor plant is showing signs of light burn then there may be other factors that are affecting your plant! This article works as a guide to help you properly identify cannabis light burn and learn solutions to help heal your plant and prevent more light stress and burn in the future. 

How to Identify Cannabis Light Burn

Light Burn Bleached Cannabis Buds

If your indoor cannabis plant is in the flowering stage, the buds can be at risk for LED light burn if using high powered LED or HPS lights that are more intense than natural sunlight. This can happen simply when your plant’s buds are too close to high powered, LED lights. This kind of light burn can be identified if your plant’s buds look white or bleached. These bleached buds are caused from too much intense light and can completely burn the cannabinoids off the buds – leaving them with very low potency THC or none at all. 

Although these ‘albino’ buds may look rare and interesting, this coloring causes extreme damage in the buds and plant itself. Bleached or white buds should be avoided at all costs. 

Yellow leaves

If light stress in plants continues over a period of time, it will eventually cause the leaves to start burning. Leaves affected by this light burn will look yellow and stained, although depending where the yellowing is on the leaves will determine what is the cause of this light burn weed. 

Signs of cannabis light burn will show prominently in the plant’s leaves. One of the first signs of light stress will show when the plant’s leaves point upward in a ‘praying’ position as if the tips of the leaves are directed towards the source of light. In the early stages of light burn, leaves will also begin to curl inward or seem more dry and brittle in texture.

Light burn weed with yellow leaves

Light burned cannabis plants will usually have yellowing on the tips and around the source of light stress. Leaves affected more on the top of the plant will look yellow or a paler green than the rest of the plant, however, the veins of the plant will remain green. Light burn creates yellow leaves on the top of the plant because the leaves have worked too hard and too long from the light source being so close. If this light stress occurs over a long period of time, even the smaller sugar leaves around the buds will turn yellow or brown.

Nitrogen Deficiency vs. Light Burn

Many times, growers will mistaken light burn for a nitrogen deficiency. Although both issues show similar signs of yellow leaves, both require different solutions to cure.

Cannabis plants can show signs of nitrogen deficiency if the plant’s leaves are yellow and wilting. Nitrogen deficiency will occur from the bottom leaves of the plant, as the nitrogen is being transferred and removed from the bottom of the plant to the top leaves to distribute the lack of nitrogen in the plant. 

The difference between nutrient deficiencies and light burn issues can be determined by how the leaves turn yellow in color in a similar way to zinc deficiency in cannabis. Light burn usually affects the top leaves of the plant, or the ones that are closest to the grow light source. These leaves will not easily wilt or fall off on their own, compared to nitrogen-deficient leaves that are found wilting at the bottom of the plant.

Effects and Solutions for Light Burn

Light burn in cannabis plants can worsen over time if presented with other issues or defects. If your cannabis plant is experiencing nutrient problems, the light burn can become more susceptible to the plant and cause worsening damage. Maintaining a cozy temperature is ideal to prevent these issues and keep the plants healthy and growing at all times. If your indoor environment ever feels too hot in temperature, then your cannabis plants certainly feel the same. 

LED Light Burn

Fortunately, light burn can be as easily solved as it can become an issue. LED grow light burning leaves are a clear sign your plant is having a light burn issue. Since light burn is mainly an issue for indoor growers, adjusting the light source is the best solution to any light burn or stress your cannabis plant is experiencing. Depending on your indoor growing space, it will be helpful to move your grow lights farther away from the plants or reduce the amount of lights in general. This will reduce the level of heat and light your plant is receiving and prevent any further issues from occurring. If you can’t easily move the light away from the plant, some growers bend their plants so that tops are farther away from the light. Or if you are in the early vegetative stage of growing, you can trim off the tops of the plant to reduce the height from being too close to the light source. 

LED light burn

Cannabis Light Burn Outdoors

Outdoor growers don’t quite run into the same light burn issue as indoor growers, since they have no control over natural sunlight! If you do happen to notice signs of yellowing or wilting leaves, check to make sure it may not be another underlying plant issue – such as overwatering or underwatering. Outdoor plants can experience light stress if their location suddenly is moved from a shady spot or indoors to full sunlight. When it comes to your plant’s environment, it’s important to make any changes and adjustments as slowly as possible. This will prevent any sudden stress or shock to your plants.

Stop Cannabis Light Burn Before it Becomes a Problem!

Light burn is something to continually be aware of throughout the growing stages of your cannabis plant. Although it may not be at risk in the early stages, plants are more at risk of light burn in the flowering and vegetative stages when the plants grow in height. The severity of light stress and burn on your plant may vary as well. If your plant is only slightly too close to the light source, then the yellowing signs of light burnt leaves may appear slowly over time rather than immediately. Be careful not to mistake older, dying leaves for light burn affected leaves! 

It’s helpful to understand that cannabis plants require the same kind of light care that humans do. If we are in the sun for too long, our skin becomes heated and burnt from the excessive amount of sunlight. This same issue can occur in plants that are experiencing too close proximity from their indoor light source. Overall, it is important to understand the effects that light burn can cause in cannabis plants. Too much sunlight will burn the plants and leaves, eventually reducing the number of important nutrients in the plant itself. By properly identifying the yellowing of your cannabis plant’s leaves as light burn, the issue can be simply solved by reducing the light or altering the distance in which the indoor lights are placed. If light burn continues for a long period of time, it can cause bleached, white buds and completely kill the cannabinoids. It’s important to look out for and prevent light burn as much as possible. Regulating your cannabis plant’s grow environment is crucial to keep your plants healthy and comfortable.