Croton plants are known for multi-colored leaves that add brightness to even the dimmest rooms. Despite their vibrant colors and patterns, crotons are still susceptible to challenges. One common issue croton owners face is yellowing or browning leaves. If you notice this issue with your croton, identifying the cause is the first step to remedying the problem. Read on to learn about the most common causes of croton leaves turning yellow or brown and how to restore your croton to a colorful form.
Common Reasons Croton Plant Leaves Turn Yellow
The primary causes of croton leaves turning yellow or brown are environmental factors such as temperature, humidity, and light. For optimal plant health, crotons require moderate to high humidity, ambient temperatures ranging from 55-85ºF, and 6+ hours of bright, indirect sunlight throughout the course of the day.
11 Common Causes of Croton Plant Leaves Turning Yellow
1. Temperature
Although croton plants enter nurseries and big box stores during cooling fall weather, they are tropical plants that require warm temperatures. Temperatures between 55-85ºF are best.
While croton plants can handle brief periods as low as 40ºF and as high as 100ºF, these conditions will stress the plant. This stress can result in yellowing leaves and also leaf drop.
Along with providing the proper temperature range, aim to avoid large swings in temperature. Therefore, if you’re moving you plant from inside to outside, or vice versa, do this gradually. You should also keep your croton away from both hot and cold drafts.
2. Low Humidity
Since they’re native to the tropics, crotons prefer moderate to high humidity. Dry air can cause the leaves to turn yellow or brown.
A humidifier is the best way to increase the humidity around your croton. However, you can also mist the air around your plant to temporarily increase air moisture.
3. Overwatering
One of the most common causes of yellowing croton leaves is underwatering. These plants like moist soil, but they will struggle in saturated soil.
The roots will have difficulty properly exchanging air if the soil is often wet. Additionally, wet soil can lead to a fungal disease known as root rot. If this disease takes hold, the roots will be unable to absorb water and nutrients properly.
A good rule of thumb is to water croton your croton when the top inch of soil is dry.
Along with keeping an eye on how often you water, you should also pay attention to your soil and pot. The potting mix should be well-draining and allow excess water to escape. The pot should also contain drainage holes.
4. Underwatering
Too little soil moisture can also lead to yellowing leaves. If croton roots do not have access to adequate moisture, they will not be able to obtain the water they need to complete important processes.
As such, the plants can become stressed and discolored. To avoid this stress, water your croton when the top inch of soil is dry. Additionally, ensure you are using a soil mix with adequate water-holding properties.
If the soil seems to be drying out only a few days after you water, you can add more peat moss or coco coir. This will increase the organic matter, which will increase the water-holding capacity.
For more, see our in-depth guide on when and how to water crotons.
5. Over-Fertilizing
While crotons need nutrients to thrive, too many nutrients can cause issues. If you apply a fertilizer that is too concentrated or fertilize too often, salts can build up in the soil. This can stress the plant and lead to yellow leaves.
If you suspect that you applied too much fertilizer, you can attempt to wash it out of the soil by watering well. You can also repot using fresh potting soil.
For more, see our in-depth guide on when and how to fertilize croton plants.
6. Insufficient Light
Crotons prefer bright yet indirect light, and lots of it. The leaves’ colors will fade if they don’t receive enough sunlight. This can include the leaves turning yellow.
To keep crotons happy, keep them in a bright location out of direct light. Some good locations for croton plants include the interior of a room with lots of windows or near a south-facing window covered with sheer curtains.
7. Direct Light
While croton plants like lots of light, they don’t like it when they are hit with direct sunlight. This is especially true if the plant was kept in a dim place and then suddenly receives direct light.
Light that is too intense can cause the leaves to become faded in appearance. This discoloration will occur rather suddenly after exposure to direct sunlight.
Keep your croton away from windows that receive direct light, or put a sheer curtain over the window.
8. Nutrient Deficiency
Like all plants, crotons need a variety of nutrients to thrive. If they lack any of these nutrients, they will not be able to complete processes adequately.
Some potting mixes have nutrients that will keep your croton happy for a few months. However, you may eventually need to apply fertilizer.
Fertilize your croton plant in the late spring and summer, about once a month. Choose a balanced houseplant fertilizer, and avoid overapplying.
9. Plant Age
While yellow leaves can be a sign of a problem, they can also be part of the plant’s natural life cycle. As a croton ages, older leaves may eventually discolor and fall off.
If new leaves look appropriately colored, discolored older leaves are likely not a cause for concern.
10. Pests
Crotons are susceptible to many of the same pests as other houseplants. These include sap-sucking pests, including aphids, spider mites, and thrips.
If these pests appear in large numbers, they may cause discolored croton leaves. Fortunately, it’s easy to identify whether or not pests cause yellowing.
Since these pests can rapidly multiply, you should remove the pests as soon as you spot them. You can use a wet, soapy rag to wipe off small numbers of pests. And if you’re dealing with a larger infestation, you can spray neem oil or insecticidal soap.
11. Repotting
Although repotting (and pruning) is sometimes a necessary part of croton plant care, it can still stress your croton. It’s normal for your plant to appear yellow for a few weeks or months after you repot it.
You can limit the stress your plant faces after repotting by providing an ideal environment.
How to Fix Yellow Leaves on a Croton Plant
The first step to fixing yellow or brown croton leaves is identifying the cause of the problem. Take a look at your plant’s environment as well as how often you are watering and fertilizing it.
If you’re unsure exactly why your croton’s leaves are turning yellow, you can still attempt to remedy the problem. Providing an ideal environment and proper care will help your plant thrive.
Keep the temperature between 55-85ºF and avoid sudden temperature swings. Aim to keep humidity moderate to high—above 50%.
As far as light goes, provide lots of bright yet indirect sunlight. If the croton doesn’t receive enough light, its leaf colors will fade. Some locations that may work well for croton include near a south-facing window covered with a sheer curtain or in the interior of a bright room.
Remember that crotons like soil that is moist but not wet. This means you should check the soil regularly and water when the top inch is dry.
You should also investigate the potting mix. The soil mix should include a mix of materials that hold water and add drainage. If you notice the soil is staying very wet or drying out quickly, you may want to repot using a different soil mix.
One final aspect of soil moisture is the pot. Your pot should have drainage holes to allow excess water to escape.
Another part of croton care is keeping an eye out for pests. By treating pests soon after they appear, you can likely avoid issues with yellowing leaves.
Yellowing Croton Plant Leaves FAQs:
How Do You Fix Yellow Leaves on a Croton Plant?
This depends on the cause of the yellowing. No matter the reason, providing an ideal environment and proper care will likely correct yellowing leaves.
Can Yellow or Brown Croton Plant Leaves Turn Green Again?
This depends on the cause of the yellowing. No matter the reason, it is possible for new green leaves to emerge.
Can Direct Sunlight Cause Croton Plant Leaves to Turn Yellow or Brown?Â
Direct sunlight can damage plant leaves and cause them to turn faded. Eventually, these faded portions can turn yellow and/or brown.
Does the Type of Water Cause Croton Plant Leaves to Turn Yellow or Brown?
Croton plants are not particularly sensitive to the type of water. However, extremely hard tap water may cause issues.
Can Over-Fertilizing Cause Croton Plant Leaves to Turn Yellow or Brown?
Yes, over-fertilizing croton leaves can cause the plant leaves to turn yellow or brown. You only need to fertilize your croton a few times a year with a low dose of houseplant fertilizer.
Wrapping Up
Now that you know the possible causes of yellowing croton leaves, it’s time to investigate which factor applies to your plant. If you’re still unsure why the leaves are yellow, aim to provide the proper environment and care to remedy the problem, and your croton should live happily for years to come.
Briana holds a B.S. in Plant Sciences from Penn State University. She manages a small market garden where she grows vegetables and herbs. She also enjoys growing flowers and houseplants at home.
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