Pepper leaves turning yellow are a sign of distress and indicate that something is wrong with your plant. The reasons for this can be numerous, including a lack of specific nutrients (nitrogen, magnesium, iron), overwatering and underwatering, diseases or pest infestations, colder temperatures, and more. In addition to these issues, there is also a chance that the soil pH is too high or too low which can directly impact the availability of certain nutrients.

The most common cause of yellowing leaves is a nitrogen deficiency which can be corrected with fertilizer. Nitrogen is important for chlorophyll which makes plants green, so adding a well-balanced fertilizer with a higher percentage of nitrogen can fix the problem. But be sure to use a slow-release formula to avoid overwatering which can also lead to yellowing leaves.

Yellowing Cucumber Plants: Unraveling the Causes and Solutions

Other nutrient deficiencies which may cause pepper plants to turn yellow include magnesium, calcium, and iron. These can all be fixed with a proper fertilizing regimen, and using crushed eggshells or crab shell nutrients will help promote healthy nutrient uptake in the soil. A magnesium deficiency can be distinguished from a nitrogen deficiency by the fact that the veins on the leaves will remain green, whereas the leaf itself will be pale yellow.

The last reason for yellowing leaves is usually due to disease or pest infestations, which can lead to wilting, stunted growth, and scorched leaf margins. Infected plants will also produce smaller fruits and less vibrant colors than healthy ones. Luckily, fungicides can be used to treat most fungal infections.