From our roots upward, a lack of sufficient water creates a state of severe stress. Our primary survival mechanism is to conserve the precious moisture we still hold. You will first notice our leaves beginning to lose their characteristic vibrant green hue, turning a dull, grayish-green. They will then start to feel dry and papery to the touch. As the drought stress continues, the most exposed leaves, typically those on the outer edges and top of the plant, will turn brown, become brittle, and crisp up—a process we call scorching. Our growth will become severely stunted; new shoots will be sparse and any existing flower production will cease as we lack the resources to support such an energy-intensive process. Ultimately, our entire form may wilt, appearing limp and lifeless.
While we yarrows are drought-tolerant, an excess of water is an even greater threat, attacking us at our foundation. Saturated soil suffocates our root system, preventing the uptake of oxygen and leading to root rot. The first aerial sign is often a general yellowing of the lower and older leaves (chlorosis), as the failing roots cannot deliver necessary nutrients. Unlike the dry, crispy leaves of underwatering, our overwatered leaves will feel soft and limp. You may notice our overall form appears wilted, but the soil will be wet—a key contradiction. The most definitive and dangerous sign is a blackening of the base of our stems and a foul, musty odor emanating from the soil, which signals advanced root rot. If this condition persists, our stems will become mushy and the entire plant will collapse.
The most crucial distinction for our survival lies beneath the soil. In underwatering scenarios, our root system remains largely healthy, albeit desperate. We will send roots deeper into the earth in a frantic search for water, but the core structure is sound. When water is finally provided, we can recover relatively quickly. Overwatering, however, destroys our very means of recovery. The roots, which should be firm and white or light brown, turn dark, slimy, and decay. This rot is often fatal because it prevents us from absorbing any water or nutrients at all, leading to a wilted appearance that misleadingly suggests a need for even more water, which only accelerates our demise.
We yarrows are built for resilience and prefer conditions that mimic our native Mediterranean habitats. We thrive in well-draining soil that allows excess water to flow away from our crown and roots quickly after a drink. We desire a deep, thorough watering only when the top few inches of soil have become completely dry. This cycle of a deep drink followed by a period of dryness encourages our roots to grow strong and deep, creating a robust and drought-resistant plant. Our leaves will maintain their fine, feathery texture and silvery-green glow, and we will reward you with prolific, sturdy blooms throughout the season.
