Daylilies (Hemerocallis) are a popular, resilient perennial prized for their vibrant flowers and minimal care requirements. Their hardiness is tied to the unique structure of their roots, which function as both a steady anchor and a sophisticated storage unit. Understanding this subterranean system is the most effective way to ensure your plants thrive, produce abundant blooms, and maintain long-term health.
Anatomy and Purpose of Daylily Roots
The daylily possesses a compound root system characterized by two distinct root types that serve complementary functions. The primary component is the network of slender, fibrous roots, which branch extensively to anchor the plant and absorb water and dissolved nutrients. These delicate roots are responsible for the immediate uptake of resources needed for daily growth.
Interspersed within this fibrous web are thicker, fleshy roots, often described as tuberous or spindle-shaped, which are specialized for resource storage. These roots accumulate carbohydrates and store excess water, creating a reserve the plant can tap into during periods of drought or stress. This substantial storage capacity makes the daylily remarkably drought-tolerant and explains its ability to survive even after being out of the ground for an extended period.
Planting and Establishing the Root System
Proper installation of a new daylily focuses on positioning the root system for optimal growth and resource acquisition. When planting, the hole should be dug wide enough—typically 12 to 18 inches—to allow the roots to spread out naturally without being cramped. It is helpful to create a small mound of soil in the center of the planting hole, draping the roots over it like a skirt, which encourages outward growth.
The most important step is ensuring the crown, the compact white area where the leaves meet the roots, is positioned correctly relative to the soil surface. The crown must be set at or just slightly below the soil line, generally no more than one inch deep, to prevent rot or desiccation. Planting too deeply can smother the crown and inhibit the development of new shoots. After backfilling the hole with soil, it should be firmed gently to eliminate air pockets, followed by a thorough initial watering to settle the soil around the roots.
Dividing Daylilies for Healthy Growth
Daylilies naturally form dense clumps as the fleshy, resource-storing roots multiply over time, which necessitates periodic division to maintain plant health. Overcrowding in the root zone leads to competition for water and nutrients, resulting in decreased vigor and significantly fewer blooms, often within three to five years. Division is best performed in the early spring as new growth emerges or in late summer to early fall after the blooming season has concluded.
To divide an established plant, the entire clump must be carefully dug up, ensuring you dig wide enough to capture the extensive root mass. Once lifted, the soil can be shaken or rinsed off to expose the individual root fans, which can then be separated by hand or cut apart using a sharp tool if the root mass is extremely dense. Each resulting division should retain a healthy set of roots and at least two to three leaf fans, which are then replanted using the same depth guidelines as new stock. Trimming the foliage back to about six inches before replanting helps the newly divided root system focus its energy on re-establishing itself in the soil.