From my roots' perspective, water is life, but it's a delicate balance. If my caretaker gives me too little water, I cannot transport essential nutrients from my soil to my leaves. My cells lose their turgor pressure, the very thing that keeps me upright and vibrant. The leaves, starting with the oldest ones, will begin to turn yellow, become crispy to the touch, and may even drop off in a desperate attempt to conserve water. Conversely, if I am sitting in constantly soggy soil, my roots are suffocating. They need oxygen to breathe, and too much water fills all the air pockets in the soil. My roots begin to rot, turning soft and brown, and can no longer absorb water or nutrients at all. Ironically, the symptoms look similar to underwatering: yellowing leaves, often starting from the lower sections, and a general wilt. The key difference is the soil's feel – it will be persistently wet.
The soil is my kitchen, and I need a balanced diet to maintain my deep green foliage and produce my fragrant blooms. A common reason for my leaves turning yellow, especially if the veins remain green, is a lack of iron. This is called chlorosis and often happens when the soil pH is too alkaline, locking the iron away so my roots cannot access it. If the older leaves are yellowing first, it might be a sign that I am deficient in nitrogen. Nitrogen is a core component of chlorophyll, the green pigment essential for photosynthesis. Without it, I simply cannot produce enough green color. While I am not a heavy feeder, my potted environment has a limited supply of nutrients that get depleted over time and washed away with watering.
As a jasmine, I thrive in bright, indirect sunlight. Think of the dappled light under the canopy of taller trees in my native habitat. If I am placed in an area with too much intense, direct sun, especially through a window, my leaves can get scorched. This sunburn will manifest as yellow or brown, brittle patches on the leaves. On the other hand, if I am kept in a deep, dark corner, I will become "leggy" as I stretch desperately for light, and my leaves will pale and yellow because I cannot perform sufficient photosynthesis. Temperature is also critical. I dislike sudden drafts, both hot from heating vents and cold from air conditioners or drafty windows. These temperature shocks can cause my leaves to yellow and drop as a stress response.
If I have been growing happily in the same pot for a few years, my root system may have completely filled the available space. When my roots become pot-bound, they form a tight, tangled mass that struggles to absorb water and nutrients efficiently, no matter how much you water or feed me. This congestion leads to stress, which shows up as yellowing leaves and stunted growth. You might even see roots circling the surface of the soil or growing out of the drainage holes, which is a clear signal that I need a new, slightly larger home.
Sometimes, the yellowing is a direct result of tiny invaders. Sap-sucking pests like spider mites, aphids, or whiteflies pierce my leaves and drain their vital fluids. This damage causes the leaves to spot, streak, and turn yellow. You might see fine webbing (spider mites) or sticky residue (honeydew from aphids) on the leaves. Fungal diseases, often encouraged by poor air circulation and overly wet conditions, can also cause yellow spotting or blotching on the foliage. It is important to inspect the undersides of my leaves regularly, as that is where these problems often begin.
