From my perspective, water is my lifeblood, but its balance is critical. My roots are highly sensitive to their environment. If you provide too much water, the soil becomes waterlogged, suffocating my root system. Without oxygen, my roots begin to rot and decay, becoming unable to transport water and essential nutrients to my leaves. This directly causes them to turn yellow, often starting with the lower, older leaves, and the soil will feel constantly soggy. Conversely, if I do not receive enough water, I cannot perform basic physiological functions. I become dehydrated and will start to conserve resources by sacrificing my oldest leaves first, causing them to yellow, wilt, and crisp up from the tips inward.
To maintain my vibrant green foliage, I require specific nutrients. A common issue is a lack of nitrogen, a fundamental building block of chlorophyll—the pigment that makes me green. Without sufficient nitrogen, my overall growth is stunted, and my lower, mature leaves fade to a uniform pale yellow. Alternatively, a deficiency in iron or magnesium also leads to chlorosis (yellowing). Iron deficiency typically shows as yellowing between the veins of my newest, youngest leaves, while magnesium deficiency appears as yellowing between the veins on the older leaves first. The soil may be lacking these nutrients, or its pH may be too high (alkaline), locking them up and making them unavailable for my roots to absorb.
Not all yellowing is a cause for alarm. If you observe my lower, older leaves gradually turning yellow one at a time while the rest of my foliage and my flowers remain healthy and vigorous, this is likely a normal part of my growth cycle. As I direct my energy towards producing magnificent new growth and blooms, I will naturally withdraw nutrients from my oldest leaves. These leaves will yellow and eventually die back to be replaced by new ones. This is simply a peaceful retirement for leaves that have served their purpose, allowing me to focus my resources on future growth.
My leaves can also yellow due to external pressures. If I am exposed to too much direct, intense sunlight, especially during the hottest part of the day, my leaves can get scorched, leading to yellowing or browning. Furthermore, if my roots are overcrowded and pot-bound, I become severely stressed and unable to uptake what I need, resulting in yellow leaves. Lastly, invisible attackers below the soil, like bulb rot fungi or nematodes, can damage my root system or bulb. This damage disrupts my entire vascular system, manifesting as yellowing, wilting leaves above the soil as I slowly decline.
