Lithodora, particularly the popular species Lithodora diffusa, is a stunning groundcover celebrated for its intense, true-blue flowers. This perennial creates a dense, low-growing mat of foliage, making it a favorite for rock gardens and borders. The general consensus among horticulturalists is that Lithodora is reliably deer-resistant, meaning it is rarely damaged by browsing animals. This distinction is important for gardeners looking to minimize plant loss in areas with active wildlife.
The Resistance Level of Lithodora
The primary reason deer tend to avoid Lithodora lies in the physical and chemical makeup of its foliage. The small, evergreen leaves of Lithodora diffusa are not smooth or tender, which makes them unappealing to a deer’s palate. The leaves and stems are often described as having a slightly hairy or fuzzy texture, which acts as a mechanical deterrent to browsing. Deer generally prefer soft, succulent plant matter that is easy to chew and digest.
Beyond the physical texture, the plant’s chemical composition contributes to its resistance. Lithodora contains compounds that impart a bitter or distasteful flavor, making the foliage unpalatable to deer. These compounds are effective at signaling to the animal that the plant is not a desirable food source. A deer will typically sample a plant and quickly move on if it registers an unpleasant taste or texture.
Understanding Deer Browsing Habits
It is important to recognize that the term “deer resistant” does not equate to “deer proof.” Deer are creatures of opportunity and necessity, and their dining preferences are heavily influenced by environmental factors. When natural food sources are abundant, Lithodora will be ignored in favor of more palatable plants. However, in situations of extreme food scarcity, such as during harsh winters or prolonged droughts, a hungry deer will eat nearly any vegetation to survive.
The density of the local deer population is another variable that can impact plant survival. In areas with high deer pressure, even resistant plants may be sampled or damaged. Young, newly planted Lithodora may be particularly vulnerable before its foliage has fully matured and developed its characteristic tough texture.
Strategies When Deer Pressure is High
For gardeners living in areas with consistently high deer activity, relying solely on a plant’s natural resistance may not be sufficient. One effective strategy is the use of physical barriers, even if temporary. Low-profile temporary fencing or netting placed around a new planting can shield the Lithodora until it is well-established. While deer can jump high fences, they are often reluctant to jump into a small, enclosed space where they cannot clearly see a landing area.
Another method involves the consistent application of taste-based or scent-based repellents. Repellents containing ingredients like putrescent egg solids or capsaicin create an immediate aversion that reinforces the plant’s natural unpalatability. To prevent deer from becoming accustomed to a single deterrent, it is necessary to rotate between different repellent products every few weeks. This practice maintains the effectiveness of the chemical barrier.
Strategic planting location can also minimize the risk of browsing. Placing Lithodora closer to the house or near heavily trafficked areas often deters deer, as they prefer to feed in quiet, secluded spots. Additionally, avoid heavy applications of nitrogen fertilizer, as the resulting flush of soft, tender new growth can temporarily override the plant’s natural resistance.