What Is Light Burn in Plants and How Do You Fix It?

TL;DR:

• Light burn happens when light is too close, too bright, or on a plant too many hours a day

• Signs: bleached, yellowing, or crispy leaves at the top of the plant that curl toward the light

• It's not a watering or nutrient problem, location of the damage is the key giveaway

• Fix it by lowering the intensity, or shortening the photoperiod

• Burned leaves won't recover, but your plant will. New growth comes in healthy once you've made adjustments

Plants grown under artificial light can thrive beautifully, but even too much of a good thing causes problems. Research shows that excessive light intensity, known as photoinhibition, can actually shut down a plant's photosynthetic process and cause irreversible cellular damage to leaf tissue. Light burn is one of the most common and most misdiagnosed issues indoor plant growers face, and it's almost always fixable once you know what you're looking for. This guide covers how to identify light burn, what causes it, and the exact steps to help your plant recover.

What Does Light Burn Actually Look Like?

Light burn shows up as yellowing, bleaching, or browning on the leaves closest to your grow light, The leaves point toward the light source rather than away from it. This upward curl or "taco" shape is one of the clearest signs that light intensity is the culprit, not a nutrient deficiency or overwatering issue.

According to horticultural science, photoinhibition occurs when a plant absorbs more light energy than it can process through photosynthesis, causing the excess energy to damage chlorophyll molecules. The result looks a lot like a sunburn; bleached patches, crispy edges, and a washed-out, pale green or white color near the top of the plant. Unlike nutrient deficiencies, which typically start at the bottom of a plant and spread upward, light burn damage stays concentrated at the top near the light source.

If you're not sure whether you're dealing with light burn or something else, Soltech's Plant Guide covers 150+ houseplants with specific lighting needs to help you narrow it down.

What Causes Light Burn in Houseplants?

Light burn is almost always caused by one (or more) of three things: the light is too close, the intensity is too high, or the light is running too many hours per day. The right hanging height makes a significant difference and it varies based on both your light and your plant's needs.

As Soltech's grow guides explain, the hanging height directly controls how much intensity your plant receives. As you raise the light, both the coverage area and light spread increase while intensity decreases, and the reverse is true when you lower it. If your light is positioned closer than the recommended height for your plant type, or your plant starts showing signs of light stress like burning or fading, that's your cue to adjust.

Running a grow light for more than 16–18 hours per day can also trigger light burn, even if the positioning is fine. Plants need a dark period each day to complete their metabolic processes, skipping it stresses the plant and compounds the effects of excess intensity.

How Is Light Burn Different from Nutrient Deficiency?

This is where a lot of plant parents get confused... light burn and nutrient deficiencies (especially nitrogen and iron) both cause yellowing leaves. The key difference is location and direction. Light burn yellows the leaves at the top of the plant that are closest to the light, and those leaves typically curl upward. Nutrient deficiencies tend to start at the bottom or oldest leaves and work their way up.

Another tell: with light burn, the yellowing is often patchy or bleached-looking not a clean, even yellow. The leaf veins usually stay green while the tissue between them fades, or the entire upper surface takes on a washed-out appearance. If you raise the light and the new growth comes in healthy, that's a strong confirmation that light intensity was the issue all along.

What's the Right Distance for a Grow Light?

The right distance depends on your plant's light requirements, not just the light itself. According to our published hanging height recommendations, here's how to position the Aspect™ Gen 2 based on what your plant actually needs:

Which Plants Are Most Vulnerable to Light Burn?

Not all plants are equally sensitive. Low-light tropicals are the most prone to light burn because they evolved under forest canopies and never developed the mechanisms to handle intense direct light. Here's a quick breakdown using Soltech's own plant light categories:

Plants in the low light tolerant category, Pothos, ZZ plants, Snake Plants are the ones most at risk when a grow light is hung too close or run at full intensity. If you're growing a mix, position your low-light plants at the outer edges of the light's coverage and let the center, where intensity is highest  serve your more light-hungry species.

How Do You Fix Light Burn? (Step-by-Step)

The good news: fixing light burn is usually straightforward. Here's exactly what to do.

Step 1: Raise the light. Increase the distance between the light and the top of your plant, referencing the hanging height ranges above for your plant type. This is almost always the fastest fix.

Step 2: Use the dimmer if your light has one. If your grow light is dimmable, reduce the output by 20–30% and gradually bring it back up over 1–2 weeks as the plant adjusts. As Soltech's Aspect™ Gen 2 grow guide notes: if your plant shows signs of light stress like burning or fading, dim the light to reduce intensity and protect your plant. The built-in dimmer gives you that flexibility without having to physically reposition anything, especially helpful for ceiling-mounted or wall-mounted setups.

Step 3: Check your photoperiod. Most houseplants need 12–16 hours of light per day. If you're running your light more than that, dial it back. 

Step 4: Remove the damaged leaves. Burned leaves won't recover, the chlorophyll damage is permanent. Trim them off cleanly at the base so the plant can redirect energy to new, healthy growth.

Step 5: Watch the new growth. New leaves that come in green and healthy after you've made adjustments are your sign that the fix worked. If new growth is still showing damage, raise the light another increment or reduce intensity further.

Can You Prevent Light Burn Before It Happens?

Yes, and prevention is much easier than recovery. The single most effective thing you can do is acclimate your plant gradually when introducing a new grow light. Plants adapt to new light environments over 1–2 weeks through a process called photoacclimation, where they adjust their chlorophyll levels and leaf structure in response to changing conditions. Start with your light at the highest recommended distance for your plant type, run it for 10–12 hours per day for the first week, then slowly decrease the distance and increase the hours over the following two weeks. Our grow guides reinforce this approach: monitor your plant's response over time and adjust height or intensity as needed, rather than setting and forgetting. If your light is dimmable, start at reduced intensity and work your way up, it removes the need to constantly reposition the fixture while your plants adjust at their own pace.

Conclusion

Light burn is a common, fixable problem. Once you know what to look for, it's easy to catch early before it causes serious damage. The burned leaves are always closest to the light source and typically curl upward. The fix is usually as simple as raising the light to the recommended hanging height for your plant type, trimming the damaged leaves, and letting fresh growth take over. Damaged leaves won't recover, but your plant absolutely will. Start at the high end of the recommended distance range, use a timer to keep your photoperiod consistent, and use your dimmer if you have one, especially when introducing a new plant to a grow light setup.