Daylilies (Hemerocallis) are resilient perennial plants known for being robust and easy to maintain. Understanding their underground structure is important for successful cultivation and maintenance, especially when dividing the clump. Unlike true lilies, which grow from bulbs, the daylily relies entirely on a unique and dense root system to sustain its vigorous growth and abundant flowering.
Visual Characteristics of Healthy Daylily Roots
The daylily possesses a dual root system originating from the crown, the solid core located between the leaves and the roots. This system consists of two distinct types of roots that grow downward and outward into the soil. Over time, the roots of a healthy daylily naturally form a dense, mat-like mass, contributing to the plant’s stability and longevity.
The first part of this system is the fine, fibrous roots, which are thin and thread-like. These structures are primarily responsible for the immediate absorption of water and mineral nutrients from the soil. The second, more defining feature is the presence of thickened, fleshy extensions along the roots.
These fleshy sections are clustered tightly around the crown and are often described as spindle-shaped or sausage-shaped. In a healthy plant, these storage roots appear firm, plump, and range in color from creamy white to light tan. They are specialized root structures, not true bulbs or tubers, despite their enlarged appearance.
The Biological Role of the Fleshy Root System
The distinctive, enlarged sections of the daylily root system function as underground storage organs. They are primarily engineered to hold reserves of water and carbohydrates, which are energy compounds created during photosynthesis. This storage capacity contributes significantly to the plant’s hardiness.
This storage capacity explains the daylily’s remarkable tolerance to periods of drought and environmental stress. When conditions become unfavorable, the plant can draw upon the stored water and nutrients within these thickened roots to survive, allowing it to remain dormant until better conditions return.
The abundance of stored energy in the root mass also allows the daylily to emerge robustly in the spring, often earlier than competing plants. This dual function of anchorage and long-term storage makes the daylily a resilient and low-maintenance perennial in the garden.
Root Structure and Daylily Division
The thick, dense root mass and fleshy storage organs become a practical consideration when dividing the plant. A large, mature clump that has not been divided for several years will have roots so tightly interwoven that they cling tenaciously. This density often requires sharp tools, such as a spade or knife, to cut the clump apart, as pulling it by hand is usually not possible.
When dividing the plant, it is important to ensure that each separated section, or fan, contains a portion of the crown and several healthy, plump storage roots. These reserves are necessary for the new division to establish itself in a new location. Conversely, roots that are dark brown or black, soft, or mushy are signs of rot or damage, and any division containing such unhealthy roots should be discarded.
The resilience provided by the storage roots means that even if some roots are cut or damaged during division, the remaining healthy portions are usually sufficient for the new plant to survive and quickly regenerate. The goal is to separate the fans while retaining as much of the healthy, creamy-white root mass as possible to guarantee the vigor of the new daylily plant.