Plant leaves turn yellow mainly because of issues affecting chlorophyll, the pigment that makes leaves green and is essential for photosynthesis. The yellowing, known as chlorosis, indicates that the plant is not getting proper care or has environmental problems. Common reasons include:

• Overwatering or underwatering: Too much water causes root suffocation and rot, leading to yellow, mushy leaves. Too little water causes nutrient deficiencies and wilting yellow leaves. Checking the soil moisture helps diagnose this.

• Poor drainage: Without drainage, water accumulates and damages roots, causing yellow leaves.

• Nutrient deficiencies: Lack of nitrogen, potassium, magnesium, or iron causes specific yellowing patterns on leaves. Fertilizing accordingly can help.

• Insufficient or excessive light: Too much sun or too little light disrupts chlorophyll production.

• Pests: Infestations by aphids, spider mites, or mealybugs weaken plants and cause discoloration.

• Being root-bound: Crowded roots limit water and nutrient uptake, leading to yellow leaves.

Thus, yellow leaves are a signal to review watering, light, soil drainage, nutrition, pest control, and pot size to restore plant health.