There are many problems that affect seasoned growers just as equally as beginners, from nutrient issues to mold and mildew almost anything can and will go wrong if given the chance. Light burn, however, is one issue that is easily avoided. Learn how to control the damage excessive light can cause your young plants and get back to growing large, healthy, productive plants right away.
Light burn is identified by a yellowing or crisping of the leaves closest to the light source. If your whole plant, for example, is turning yellow, pest or nutrients are more likely to blame. Light burn only affects the very tops of the plants. In the mildest cases, you’ll see the veins of the plant remain green while the outermost edges turn a faint yellow. In severe cases, the plant will begin to die back, the leaves will turn dark brown, turn inward and become crisp. If left, the plants will pose a fire risk to their environment.
Light buds, white buds:
If your plant has begun to flower and you notice a pure white or light yellow bud, you haven’t just discovered a rare strain of cannabis! Light burnt buds will turn white due to light bleaching. These bleached buds have almost no THC and no positive cannabinoids, as the light has bleached them away.
Fixing the issue:
If you’ve started to notice light burning on your young plants it’s not too late to prevent further damage. Raise the light fixture to a higher level above the plants or change out the bulb to a lower power. Monitor your plants closely after you notice light burning to prevent the damage from worsening. Never change your watering pattern unless the plant is dangerously dry. Overwatering will not repair the damage caused by light, rather, it will introduce new problems to your plants.
Light stress in outdoor plants:
If your plants are outdoors and showing signs of light stress you obviously can’t increase the distance from the sun to the leaves. What’s far more likely is the plant was raised in a more shaded area and is used to a lower amount of light. You’ll need to move the plant back to a shaded area or create a shade for the plant if it cannot be moved.
What if this didn’t work?
Lots of other things can imitate the damage caused by light stress. If moving the lights or creating shade didn’t work for your plants you may see if your plants are suffering from heat stress. Other possible issues could be a pest, parasite, or nutrient deficiency.