Coral Bells (Heuchera) are popular, shade-tolerant perennials valued for their diverse foliage colors and textures. For gardeners in areas with high browsing pressure, the good news is that Heuchera is considered highly resistant to grazing by deer populations.
The Mechanism of Resistance
Deer tend to avoid Coral Bells due to a combination of physical characteristics and chemical compounds present within the foliage. The leaves of many Heuchera cultivars possess a fuzzy, hairy, or leathery texture. This surface structure acts as a mechanical deterrent, making the leaves less palatable and difficult for deer to chew comfortably.
Beyond the physical texture, the plant employs a chemical defense system that further discourages consumption. Heuchera foliage contains various secondary metabolites. These compounds serve protective roles and contribute a bitter or pungent flavor profile to the leaves.
The unpleasant taste signals to the deer that the plant is not a desirable food source, causing them to move on quickly. This defense mechanism makes the plant unappetizing, ensuring it is rarely consumed in quantities that cause significant damage.
Contextualizing “Deer Resistant”
The designation “deer resistant” does not equate to “deer proof” under all circumstances. A plant’s natural defenses can be overridden by environmental factors that increase the pressure on deer to find food. Conditions of extreme hunger, such as drought or harsh winter, can force deer to consume plants they would normally ignore.
When native forage is scarce, the deer’s dietary preferences become significantly less selective, leading to browsing damage on even highly resistant plants. Regional differences in deer populations and their established diets can also influence which plants they choose to eat. A local herd may have developed a tolerance or preference that is unusual for the species as a whole.
The age and maturity of the plant also play a role in its vulnerability to grazing. Newly planted or very young Coral Bells are often more susceptible to damage than mature specimens. The tender, new growth lacks the robust texture and concentrated chemical defenses found in established, older foliage.
Heavily fertilized plants can also be more attractive to deer, as the resulting rapid, soft growth is easier to consume. While Heuchera is highly rated for resistance, no plant offers a complete guarantee against a determined and hungry animal. Understanding these external variables helps manage expectations for landscape protection.
Mitigation and Companion Planting
For landscapes under significant deer pressure, combining the plant’s natural resistance with active mitigation strategies offers the best protection. Physical barriers, such as temporary wire cages or netting, can be deployed to protect newly installed Coral Bells during their initial establishment period. This simple measure allows the young plants to mature and develop their inherent defenses before being exposed to browsing.
Repellent Sprays
The use of commercial deer repellent sprays can supplement the plant’s natural resistance, especially during periods of high vulnerability. These repellents often employ strong odors or tastes, typically containing egg solids or capsaicin, that are offensive to deer. To maintain effectiveness, these products should be reapplied after rain. Rotating between different repellent types prevents deer from becoming accustomed to a single scent or flavor, thereby maintaining the deterrent effect.
Companion Planting
Gardeners can integrate protective measures into a broader strategy involving companion planting. Strategic placement of other highly deer-resistant species creates a less appealing overall environment for browsing. Companion plants with strong aromatic qualities, such as lavender (Lavandula) or Russian sage (Perovskia), help to mask the subtler scent of the Heuchera foliage. Plants with rough or highly textured foliage, like lamb’s ears (Stachys byzantina), also serve as physical deterrents when planted in proximity. Creating a layered defense significantly reduces the likelihood of browsing damage.