Spiderworts (Tradescantia) are common perennials prized by gardeners for their vibrant, three-petaled flowers and adaptability. Spiderwort plants are generally categorized as deer-resistant, meaning they are not a preferred food source for white-tailed deer. However, this designation does not make the plants entirely deer-proof. When preferred food sources become scarce, deer will browse on plants they would otherwise ignore, requiring gardeners to focus on deterrence rather than relying solely on the plant’s natural defenses.
Why Spiderwort is Not a Preferred Food
The low palatability of spiderwort stems from specific physical and chemical properties that deter browsing animals. Deer are highly selective eaters, preferring tender, nutrient-rich foliage, and they avoid plants with difficult textures or unpleasant flavor profiles. Certain varieties, such as the Prairie Spiderwort, possess tough foliage and sap-rich stems that make them less appealing.
The plant’s internal chemistry also contributes to this natural defense, as deer shun vegetation containing bitter compounds or strong aromas. The inner consistency of a spiderwort stem contains a mucilaginous secretion that becomes threadlike when cut, giving the plant its common name. This slimy texture is physically unappealing to a browsing deer, which prefers a clean bite over a difficult, stringy chew.
When Deer Are Most Likely to Graze
Even naturally resistant plants, including spiderwort, can fall victim to browsing pressure when external factors override a deer’s natural aversion. The primary driver for deer to consume non-preferred plants is the scarcity of their typical diet, which occurs most often during seasonal transitions. Browsing is heaviest in late winter and early spring, when stored forage has been depleted and new shoots have not yet fully emerged.
In spring, the new growth on spiderwort plants is more vulnerable than mature stems, as young shoots are higher in moisture and nutrients, making them temporarily more palatable. High local deer population density also forces animals to expand their diets and consume less desirable vegetation to meet nutritional requirements. This extreme hunger overrides the sensory signals that normally tell a deer to avoid the plant, leading to damage.
Effective Strategies for Plant Protection
Gardeners can employ a layered approach to protect spiderwort, focusing on physical and sensory deterrence. One reliable method involves using small physical barriers, such as constructing wire cages or cylinders around individual plants or clusters of new growth. This simple fencing needs to be tall enough to prevent a deer from reaching over to nibble the foliage, typically requiring a height of at least 24 inches for low-growing perennials.
Another effective strategy is the use of repellents, which target a deer’s sense of smell and taste. Commercial repellents, often containing dried blood or putrescent egg solids, should be rotated every few weeks to prevent deer from becoming accustomed to a single scent. Granular repellents or strong-smelling household items like scented soap can be placed near the plants to create a sensory barrier. For a non-chemical solution, strategic companion planting involves placing fragrant or fuzzy-leaved plants like lavender, thyme, or lamb’s ear near the spiderwort to mask its presence and deter browsing.