First, do not be alarmed. From my perspective, this yellowing is often a natural and expected part of my life cycle. I am a herbaceous perennial, which means my above-ground growth is not meant to last forever. As my blooming period concludes, typically by mid-summer, my energy begins to retreat. I must pull valuable resources back into my roots and crown to store them for the winter. The leaves that have served me so well begin to yellow and die back. This is not a sign of distress, but one of preparation for my dormancy. I am simply going to sleep and will return with fresh growth when the conditions are right again in the spring.
If my yellowing occurs outside of my normal dormancy period, you must consider my water needs. My name, Bleeding Heart, is a clue to my preferences. I enjoy consistently moist, well-hydrated soil, much like the cool, damp forest floors from which I originate. If I am left thirsty and the soil becomes too dry, my leaves will turn yellow and crisp as a clear signal of my distress. Conversely, if my roots are drowning in waterlogged soil, you are suffocating me. Soggy conditions prevent my roots from absorbing oxygen, leading to root rot. In this case, my leaves will turn a soft, mushy yellow. The goal is soil that feels like a well-wrung sponge—moist but not saturated.
My foliage is sensitive to its environmental conditions. I thrive in partial to full shade. If I am planted in a location where the sun is too intense, especially the hot afternoon sun, my delicate leaves can become scorched. This sunscald will cause them to yellow, bleach, and often develop brown, crispy edges. Similarly, a sudden late spring frost can damage my new, tender growth, causing it to blacken and yellow. I prefer a stable, cool environment, and extreme fluctuations in temperature or light can cause me significant stress, manifesting as yellowing leaves.
Like all living things, I require nutrients to sustain my lush growth and prolific bleeding heart flowers. If the soil I am growing in is nutrient-deficient, particularly in key elements like nitrogen, I cannot produce the chlorophyll that gives my leaves their healthy green color. This deficiency will cause a general yellowing, often starting with the older leaves. However, an excess of fertilizer can be just as harmful, causing fertilizer burn to my roots which also results in yellowing or browning leaves. A gentle, balanced feeding in the early spring is usually all I require to flourish.
Any significant disturbance to my root system is a major event. If I have been recently divided or transplanted, I will direct my energy away from my leaves and toward re-establishing my roots in their new environment. This transplant shock commonly results in temporary yellowing and wilting. Furthermore, as I mature and my clump grows larger, I may become overcrowded. This competition for space, water, and nutrients in the soil can lead to yellowing leaves and reduced flowering, indicating it may be time to gently divide me in the fall.
