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Why Are My Coleus Plant Leaves Turning Yellow?

Updated: January 11, 2023

Coleus plants are popular for their beautiful, colorful foliage. However, when the leaves turn yellow, it can be a cause for concern. Yellowing leaves can indicate a variety of issues that could be harmful to your plant’s health. In this article, we will explore the reasons behind why your coleus plant leaves are turning yellow and what you can do to fix the problem.

Overwatering

Overwatering is one of the most common reasons why coleus plant leaves turn yellow. When the roots of the plant are constantly sitting in water, it can lead to root rot and cause the leaves to turn yellow or brown. If you notice that the soil is consistently moist or soaking wet, reduce watering intervals or allow the soil to dry out between waterings.

Underwatering

On the other hand, underwatering can also cause yellowing of coleus plant leaves. When a plant is not receiving enough water, it will start to conserve resources and drop its lower leaves. Check the soil moisture regularly and water your plant when the top 1-2 inches of soil feels dry.

Nutrient Deficiency

Yellowing leaves can also indicate a nutrient deficiency in your coleus plant. Nitrogen deficiency is one of the most common culprits, which causes pale yellowing of older leaves. Ensure that your plant is receiving enough nutrients by fertilizing regularly with a balanced fertilizer.

Too Much Sunlight

Coleus plants prefer bright, indirect sunlight but too much direct sunlight can cause damage to the leaves. If your plant is placed in a spot with too much direct sunlight, it may start to show signs of stress such as yellowing or brown spots on the leaves. Move your plant to a spot with bright but indirect sunlight to prevent further damage.

Pests and Diseases

Pests such as spider mites and mealybugs can cause yellowing of coleus plant leaves. These pests feed on the plant’s sap, which can lead to yellowing, curling and wilting of the leaves. Diseases such as fungal infections can also cause yellowing of the leaves. Inspect your plant regularly for signs of pests or diseases and take appropriate measures to control them.

Root Bound

When a plant outgrows its container and the roots become root-bound, it can cause stress to the plant and lead to yellowing of the leaves. Repot your coleus plant into a larger pot every 1-2 years to ensure that it has enough space to grow.

FAQ

How do I know if my coleus plant is overwatered or underwatered?

Overwatered plants will have consistently moist soil or pooling water at the bottom of the pot, while underwatered plants will have dry, crumbly soil.

Can I save my coleus plant if the leaves have turned completely yellow?

It depends on the severity of the damage. If only a few leaves have turned yellow, you can remove those leaves and take steps to fix the underlying issue. However, if most of the leaves have turned yellow and are falling off, it may be too late to save the plant.

How often should I fertilize my coleus plant?

Fertilize your coleus plant once a month during the growing season (spring and summer), using a balanced fertilizer with equal amounts of nitrogen, phosphorus, and potassium.

In conclusion, yellowing of coleus plant leaves can be a sign of various issues ranging from overwatering to pests and diseases. By identifying the underlying cause of yellowing and taking appropriate measures, you can help your coleus plant recover and thrive.