Light Burn

Problem: Your cannabis plant can only withstand a certain amount of light. After a certain point, your cannabis will start exhibiting signs of stress on the leaves near the sources of light and/or heat. Your leaves will get yellow or brown spotting, often with burnt tips/edges and margins that stay green. Leaves may also appear generally burnt in places when there's too much light, especially when combined with heat

How can there be too much light? Read the full guide

Here's more cannabis light burn pics...

Light stress often first appears around the edges of leaves, while inside veins stay green

This cannabis seedling is being burned by too-close LED grow lights

This cannabis seedling basically grew up into the grow light! The heat from the bulb caused massive burning everywhere it touched. If a plant's leaves directly touches the lights, it leaves "burns" from the heat of the bulbs.

Light Bleaching Cannabsi Buds

This is how you get "albino" buds. Light bleaching is most common with high-power LEDs and HPS lights that are kept too close to the tops of the plants. Basically, this is what happens when plants get too much light, kinda like how hair on top of your head can turn lighter if you spend plenty of time in the sun, except a "sun-burnt" bud isn't as strong!

Buds which have been bleached tend to be low potency or even have no potency (no available THC or other cannabinoids). Therefore you should avoid light-bleaching your plants at all costs!

Sometimes light-bleached cannabis will get mis-labeled as “albino cannabis” or “white cannabis” but the truth is that the white color is not healthy, so this is not a desirable trait (even if it looks pretty cool).

Solution: If your marijuana plants are getting too much light, try removing some of the lights or moving your grow lights further away from the tops of the plants.

It is unlikely for your plants to get "light-burned" from the sun when growing outdoors, and they definitely can't accidentally grow into the sun. Outdoor plants can show signs of light stress if plants were used to shady conditions and moved into direct sunlight without time to get accustomed to the brigher light levels.

When making changes to your plant's environment, it's best to make changes slowly if possible. Slow gradual changes are best for preventing stress when growing indoors or outdoors.

Sometimes heat stress can look like light stress. When learning how to grow cannabis, it's best to try to keep things at a comfortable temperature at all times for optimal growth. If it's too hot for you, it's probably too hot for your plants. Outdoors, things can be a bit harder, but there are steps you can take to protect your outdoor plants from the heat. Learn more about cannabis heat stress.

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