The cheerful, daisy-like perennial known as Tickseed (Coreopsis) is a popular addition to North American gardens, valued for its long blooming season and bright color palette. Gardeners often seek out resilient plants for their landscapes, but a common challenge is the presence of white-tailed deer whose browsing can quickly destroy vulnerable foliage. Protecting garden investment from these persistent herbivores is a primary concern for homeowners, leading many to question the palatability of their chosen ornamentals. Understanding which plants deer avoid is a practical step in designing a resilient garden space.
Tickseed and Deer Resistance
The definitive answer to whether deer eat Tickseed is generally no, making it a reliable choice for areas with high deer populations. Most varieties of Coreopsis are rated as deer-resistant because the plants possess natural deterrents that make them unappealing to browsing animals. This resistance is often attributed to the presence of secondary metabolites, such as terpenoids, that impart a bitter or unpleasant taste to the foliage.
The texture of the leaves also plays a role in this defense mechanism, as deer tend to avoid plants with fine, lacy, or hairy surfaces. While no plant is entirely deer-proof, Tickseed’s combination of chemical defense and physical texture means it is rarely the preferred food source.
Factors Influencing Deer Grazing
While Tickseed is largely avoided, it is possible for deer to browse on it under certain environmental conditions. Deer are opportunistic feeders, and their usual preferences can be overridden by extreme hunger or a scarcity of alternative, more palatable forage. During periods of drought, heavy snow cover, or late winter when natural food sources are severely limited, deer may sample or consume plants they would normally ignore.
Deer behavior can also vary based on local population density and regional diet. In areas with high deer concentration, competition for food increases the likelihood of resistant plants being tested for edibility. Deer often show a preference for tender, new growth over mature, hardened foliage. Young Tickseed transplants or fresh spring shoots may be more vulnerable to browsing than fully established plants later in the season.
Strategies for Deer Management
Gardeners should assume that even deer-resistant plants can be at risk and implement a layered protection strategy. Physical barriers are the most effective method, requiring permanent fences to be at least seven to eight feet tall to deter a determined deer from jumping. As an alternative, a double-fence design with two parallel, shorter fences spaced a few feet apart can confuse the deer and prevent them from clearing the barrier.
Repellents offer a secondary defense that works by taste or smell, but they require consistent management. Taste-based repellents containing sulfur compounds, like rotten egg solids, are often the most effective at conditioning deer to avoid the treated area. These products must be rotated and reapplied frequently, particularly after rain or whenever the plants put out new, unprotected growth. Companion planting can also help by placing highly aromatic, non-preferred herbs near more vulnerable plants, using the strong scent to make the area less appealing to a foraging deer.