Plant care: Identifying nutrient deficiencies and watering issues

Identifying the cause of yellowing leaves in plants requires distinguishing between nutritional deficiencies, watering issues, and pathogens to avoid improper use of fertilizers or pesticides.

Nutrient deficiencies often follow the physiological mobility of elements. Mobile nutrients typically show symptoms in older leaves as the plant relocates them to new growth, whereas immobile nutrients manifest in new leaves and terminal buds. Technical guidance from Embrapa suggests that analyzing lesion distribution patterns and soil history is essential for accurate diagnosis.

In gardening, yellowing can also indicate improper hydration. While dehydration causes discoloration, overwatering can suffocate roots, leading to rot and a lack of oxygen. Key indicators of overwatering include soft, yellow leaves, dark or mushy roots, and soil that remains damp or smells of mold. Improving soil drainage by adding sand, pine bark, or perlite can help prevent these issues.