Spiderwort, a member of the genus Tradescantia, is a popular perennial valued for its striking, three-petaled flowers that bloom across a range of colors. These plants are often used in garden borders or naturalized areas, providing a reliable splash of color throughout the season. For many gardeners, the practicality of a plant hinges on its ability to survive browsing pressure from local wildlife, particularly white-tailed deer.
Gardeners and horticultural experts generally categorize spiderwort as moderately to highly deer-resistant. This designation means that while the plant is not deer-proof, it is usually among the last choices for a deer seeking a meal. The primary reason for this resistance is rooted in the plant’s texture and chemical composition. When the stems or leaves of spiderwort are broken, they exude a sticky, mucilaginous sap.
This syrupy fluid, which gives the plant its common name, is often unappealing to a deer’s palate. The foliage itself is also fleshy and sometimes contains compounds that contribute an unattractive flavor to the plant. Deer are known to prefer soft, tender, and highly palatable vegetation, making the slightly sticky and unappetizing nature of mature spiderwort a natural deterrent. This resistance is not a guarantee, however, and deer will occasionally “taste test” a plant.
Factors That Reduce Deer Resistance
The categorization of spiderwort as deer-resistant can be misleading because several environmental and situational factors can quickly turn the plant into a target. Deer will abandon their preference for unpalatable plants when the availability of their usual food sources diminishes. During periods of drought or in the late winter when other vegetation is scarce, a hungry deer will become far less selective in its diet.
Scarcity and Population Pressure
High population pressure is another significant variable that increases browsing activity. In areas with an overabundance of deer, competition for food forces the animals to consume plants they would normally ignore, including spiderwort. A plant’s resistance is directly proportional to the number of available alternatives. When those alternatives are exhausted, even a highly resistant plant may be browsed down to the ground.
Plant Age and Variety
The age and specific variety of the plant also play a role in its vulnerability. Newly planted spiderwort, with its tender, unestablished root system and soft new shoots, is significantly more palatable than older, mature foliage. Furthermore, the Tradescantia genus includes over 80 species. Many modern, highly hybridized cultivars may have had the defensive compounds bred out of them in favor of more desirable flower or foliage traits, making them a more inviting snack for browsing deer.
Practical Strategies for Plant Protection
When spiderwort is being browsed, gardeners must move beyond relying on the plant’s natural defenses and implement active protection measures. One of the most effective short-term solutions is the application of commercial deer repellents. These products work by utilizing strong odors or bitter tastes, often containing ingredients like putrefied egg solids, garlic, or capsaicin. It is advisable to rotate between two different types of repellents to prevent deer from becoming accustomed to a single scent or flavor.
Physical barriers offer the most reliable long-term protection, though they require more effort. For newly planted spiderwort, temporary wire cages or netting can be installed to protect the vulnerable young growth until the plants mature and establish their natural deterrent qualities. In areas where deer pressure is intense, a permanent physical exclusion barrier, such as an eight-foot fence, is the only way to ensure zero browsing damage.
A softer approach involves companion planting, which uses a plant’s natural characteristics to shield a more vulnerable neighbor. Planting highly aromatic herbs or vegetation with rough, fuzzy, or spiky textures near the spiderwort can help mask its scent and deter deer from approaching the area. Strong-smelling plants like lavender, mint, or bearded irises confuse a deer’s sense of smell, making it less likely to locate the spiderwort.