Light burn & light stress on marijuana plants

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There is only so much light your marijuana plant can take. At some point, the plant will show evidence of strain around the main points where it receives light. Brown or yellow spots will show up on the leaves, followed by burnt tips and the borders will remain green.

In the spots where it’s getting an excess of light, the leaves will look burnt. Learn how to identify and prevent light burn on your marijuana plants.

What is light burn?

Your buds can turn albino through light bleaching. This frequently happens with high-power LEDs and HPS lights that are placed too close to the top of the plant. As a result, your plant gets way more light than it needs. Once your buds are burnt, their strength diminishes and may get to the point to where it has no THC. So, the moral of the story is: make sure you don’t give them too much light to prevent any bleaching.

What is light burn

Calling light-bleached marijuana names such as “white cannabis” or “albino cannabis” is not a good thing. The fact that it is white is a sign that it is in bad condition. This is not what you want.

You can also reduce stress by protecting the core of the plant itself, using my Plant Protector kit.

Marijuana Plant Protector Set

Marijuana protector set

  • Protection against diseases and pests
  • Consists of three 20 ml bottles
  • Enough plant protection for 20 plants


How to fix light burn

If you think the plants are getting more light than is necessary, start by sliding the grow light farther from the top of the plants.

How to fix light burn on marijuana plants

Light bleaching because of sunlight is very rare when outdoor growing and there is no way they will ever get too close to the sun. If you move your plants from a bad situation, then into the sun they may display signs of light bleaching if they never had a chance to adjust to the increase in light.

Also read From light to growth: Growing the best weed with light

Take it slow when adjusting your plant’s conditions. You don’t want to stress your plant out for either outdoor or indoor growing.

Maintain a cozy temperature consistently for the best results and health. Think about it like this, if you feel like it’s too hot, then certainly it’s too hot for the plants. Things aren’t as simple for outdoor growing, but take the time to learn what to do for outdoor heat.

Marijuana plant symptoms

Plant symptoms of cannabis light burn

Leaf symptoms

  • Tips / Edges are burnt or brown
  • Leaves turn pale in color
  • Brown spots
  • Top leaves / new growth is damaged
  • Veins of leaves remain green

To grow healthy marijuana plants despite stress introduced by light burns, make sure to get seeds with strong genetics. Usually, they fare well even in harsh environments. I have created multiple grow sets which features all you need in order to grow healthy plants from seed to harvest!

Resilient grow kit

FAQs about cannabis light burn

What are some common symptoms of light burn on weed?

If you notice that the tips/edges of your plant’s leaves are burnt or brown or pale and that new growth is damaged, your plant is most likely experiencing a light burn.

How do you prevent light burn on marijuana plants?

Always maintain a cozy temperature consistently for the best results and health of your plants.


Have you ever dealt with light burn on cannabis plants? Please leave comments or questions below.

Download my free grow bible to learn more about light burn on marijuana plants and how to prevent it.

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  • Avoid common grow mistakes


    Happy growing!

    Robert

    Avatar for Robert Bergman

    Robert Bergman

    Robert Bergman is an Amsterdam-based marijuana grow expert who has years of experience from small grows to massive operations. His passion for growing led him to develop his own Gold Leaf strain. Now, Robert is dedicated to sharing his knowledge with the world.... [Read full bio]

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    GROW BIBLE

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      14 comments on “Light burn & light stress on marijuana plants”

      1. My seedlings have turned white from the inside of the leaves these last few days. I did take them outside from my sun porch where they had been growing. It also turned cold and I brought them in at night.

      2. my light rig has failed at 106 days, was beginning to flush for a harvest date of 91318; I cannot get another rig for 36 hours. Should I harvest now?

      3. myplants are 4 weeks ihto veg starterted showing burt tleaf tips then started curling .I Set the liights further back .immediaty started looking better but still worried about the clawing and twisting that took place. .will they be o.k now?

      4. Jared,

        Never run lights all day. 19 hours a day max. I jhave no idea what type lights you have so I cannot advise you. I will say that flood lights are generally not suited to growing, but you said you had a “grow flood light???”.

        You would be better served to go and join our support forum. There you can post pictures and get the informed advice that you need.

        See you there! 🙂

      5. I have one that is light burned. Used a R30 65watt flood grow bulb and a 15watt florescent black light. I recently just purchased a 15watt florescent plant and aquarium bulb. I now run the F15 all day and turn on the flood light every now and then. The F15 is about 5½ inches away and the flood light is 12½ inches away.have one backside long mirror behind. With both lights on it is warm to the hand. Finally there is hope. Any ideas on just how far to put both lights full blast? All day?

      6. I bought 15 seeds, 5 of 3 different types, i planted 2 of each (6). All 6 started to grow. I thought this will be great. Im growing indoors in a fish tank. Foil insides to help with light, flouresant lights on top of tank on the floorin my closet, i keep Door open. I also fan a fan in the closet to help move air circulation. I started using distilled water, then i read that water doesnt really matter so i went to tap water the plants got to 4 to 5 ” in height, there is only 4 left, and they are not looking good either, dam a costly experience…..i failed

      7. How would the combination of a 400 watt H/P and a 1200 watt 10 watt split LED work for getting the best of thoes worlds be for my girls?? Buy the way great seeds.

      8. trisha,
        You adjust your AC to a setting you feel comfortable with. Ideally, you want you temps to be between 70-80f, or 20-25c.

        In order to get temperatures stable, you adjust the AC day by day, until you find the right range of settings. Once you have the temp adjustment stabilized, you will be good to go.

      9. Andrew,

        You have to be patient. I am not sure starting the seeds in Black Gold. That soil may be too hot for seedling, but you will find out shortly. If tips start to curl, and dry out, the soil is too hot.

        One does not add nutrients to plants until they have 4-5 strong sets of leaves. With that soil; You probably will not have to add nutrients until the plant is in the flower stage. Hope this helps.

      10. I got five AK-48’s. Two of the five didn’t pop (so sad). One of the other three is looking good. The other two sprouted but are slow growers. They have very thin stems, is that normal? I started these on July 20th. They are being grown in half gallon pots outside. I will transfer to five gallon buckets and bring them inside if they live. I’m using Black Gold soil and tap water. The water comes from a natural reservoir thru a treatment plant. I’ve used no additives yet, nor have I checked PH. This is my first attempt at growing. Will use for nerve pain if it will help. If anything I should get a good buzz. Any suggestions???