Rudbeckia, commonly known as Black-Eyed Susan, is a popular addition to many gardens, prized for its cheerful yellow petals and dark centers. This native North American wildflower is often sought after by gardeners dealing with deer damage. Understanding the plant’s standing regarding its palatability to browsing animals is important for successful cultivation. This article explores the biological defenses of Rudbeckia and provides practical strategies for plant protection.
Why Deer Typically Avoid Rudbeckia
Rudbeckia is classified as deer-resistant due to specific physical and chemical characteristics that deter browsing. The most immediate deterrent is the coarse, hairy texture (pubescence) of the leaves and stems. This rough surface is unappealing to deer, which typically prefer plants with tender, smooth foliage for easier ingestion. Beyond the texture, the foliage also contains secondary compounds, such as phenolic acids and flavonoids, that contribute to a bitter taste. These chemicals accumulate in the plant tissue, acting as a natural defense mechanism against herbivores. While this resistance is strong, gardeners should remember that “deer-resistant” does not equate to “deer-proof.”
When Resistance Fails: Factors That Encourage Browsing
Despite the plant’s inherent defenses, certain environmental variables can override a deer’s natural aversion to Rudbeckia. The most significant factor is extreme hunger or food scarcity, which compels deer to sample plants they would normally ignore. This is evident during late winter or periods of severe drought when preferred food sources are depleted. High local deer population density also increases the likelihood of browsing, forcing animals to expand their diet to less desirable items. Furthermore, the age of the plant matters; deer are more likely to sample the tender, new shoots of young Rudbeckia in the spring than the tougher, fully matured foliage that develops later.
Proven Methods for Protecting Your Plants
Gardeners facing persistent deer pressure must implement proactive measures to protect their Rudbeckia and surrounding plantings. Physical barriers offer the most reliable form of protection, with fencing being the gold standard. A standard deer fence should be at least eight feet high to prevent deer from jumping over. For smaller gardens or individual plants, temporary wire cages or netting can be placed directly over the plant, which prevents the deer from accessing the foliage.
Chemical deterrents are also effective, working through both scent and taste to repel deer. These commercial sprays often contain ingredients like putrefied egg solids. Sprays should be rotated periodically, as deer can become accustomed to a single smell or taste over time.
Strategic companion planting can also bolster the defense of Rudbeckia. Placing plants with strong aromas or unpleasant textures, such as lavender, sage, or aromatic herbs, around the Black-Eyed Susan helps mask its presence and creates a repellant border. Ultimately, while Rudbeckia offers a high degree of natural resistance, a multi-layered approach combining these methods provides the best assurance against damage.