From my roots' perspective, water is a constant negotiation. If my soil becomes too dry, I cannot uptake the water and dissolved nutrients I need to sustain my vibrant green foliage. My cells lose turgor pressure, and my leaves begin to wilt and turn yellow as chlorophyll breaks down. Conversely, if my pot lacks proper drainage or I am watered too frequently, my roots are suffocated. They rot in the oxygen-deprived, soggy soil. Once my root system is damaged, it cannot function, and the same symptom appears: my leaves turn yellow because my damaged roots can no longer deliver water or sustenance to the rest of my body, effectively leaving me parched even in wet soil.
To maintain my prolific flowering and lush growth, I am a heavy feeder. The yellowing of my leaves is often a direct cry for specific nutrients. A common issue is a lack of nitrogen (N), which is a fundamental component of chlorophyll. Without it, my older leaves typically turn a uniform pale yellow as the nitrogen is mobilized to support new growth. In other cases, if my veins remain green while the tissue between them turns yellow (a symptom called interveinal chlorosis), I am likely suffering from an iron deficiency. This often occurs when the soil pH is too high, making iron unavailable for me to absorb, even if it is present in the fertilizer.
As a fast-growing plant, I can quickly exhaust the resources within my container. When my root system has filled the pot entirely, it becomes a tangled mass with little room to grow and very little soil left to hold moisture and nutrients. Every time you water me, the water may just run straight through without properly hydrating the root ball. This leaves me perpetually under stress, unable to access what I need, and my leaves will signal this distress by turning yellow. My roots need space to explore and gather resources.
Yellowing leaves can also be a visible sign of a biological assault. Aphids and spider mites are tiny pests that pierce my leaves and stems to suck out the nutrient-rich sap. This feeding damage directly causes stippling, wilting, and yellowing of the affected foliage. Furthermore, these pests can transmit viruses that also lead to yellow mottling or patterns. Fungal diseases, often encouraged by overhead watering or poor air circulation, can attack my crown and root system, leading to rot which, again, manifests as yellowing and wilting leaves above the soil.
While I thrive in full sun, extreme conditions can cause stress. Intense, scorching sunlight combined with high heat can sometimes lead to sunscald, bleaching and yellowing my leaves. More commonly, a sudden drastic change in my environment—such as moving me from a sheltered nursery to a windy, full-sun patio—can trigger a stress response where I shed older leaves (which turn yellow and drop) to conserve energy for new growth better adapted to the new conditions.
