Heuchera, commonly known as Coral Bells, are highly valued perennial plants celebrated for their wide variety of colorful foliage. They do not spread aggressively like plants that use runners or rhizomes. Instead of moving horizontally, they maintain a stationary base and expand slowly in a tight, vertical manner over many seasons.
The Clumping Growth Habit
Heuchera plants are clump-forming; their leaves grow directly from a central, woody base called the crown. This growth habit differs significantly from true spreading plants, which send out horizontal stems like stolons or runners. The plant’s mature spread is typically a compact mound of foliage, ranging from 1 to 2.5 feet wide, depending on the cultivar.
The expansion of a single plant is internal, focusing on increasing the diameter of the leaf mass above the ground. This consistent, non-invasive mounding structure makes Heuchera an excellent choice for borders and defined garden spaces. Their root system is relatively shallow, which contributes to their compact nature but also makes them susceptible to movement under certain conditions.
How Heuchera Plants Expand
Heuchera increases in size through the elongation of the central crown, rather than outward horizontal spread through underground stems. Over several years, the woody base grows upward, creating a visible “neck” above the soil line from which new leaves emerge. This upward growth is characteristic of the plant’s aging process.
As the crown elongates, the plant can become “leggy,” with the lower portion of the stem becoming bare and woody. This phenomenon can cause the plant to become unstable or less vigorous because the roots are no longer fully anchored or covered by soil. Minor self-seeding can also occur, but these seedlings are rarely true to the parent cultivar.
Rejuvenating and Dividing Mature Plants
Due to this upward growth, mature Heuchera often require maintenance every three to five years to restore vigor. When the woody crown becomes exposed and performance declines, rejuvenation is necessary. This process involves either replanting the crown deeper into the soil or dividing the plant into smaller, healthier sections.
The best time to divide Heuchera is in the early spring or fall to allow the new sections time to establish roots before extreme weather. To divide, carefully dig up the clump and locate the woody, unproductive central core. Healthy new growth, found around the edges of the clump, can be cut or pulled away, ensuring each division has a few leaves and some roots attached. The old, woody center should be discarded, as it rarely produces strong new growth. When replanting the divisions, bury the lower, woody portion of the stem, placing the crown so that the base of the leaves is just at the soil level. This technique prevents the common issue of “heaving,” where shallow-rooted plants are pushed out of the soil by freeze-thaw cycles.