Deer browsing can be a persistent challenge for gardeners. While no plant is truly immune to a hungry deer, many perennial varieties possess natural defenses that make them highly unpalatable. This article focuses on identifying these “deer-resistant” perennials, which are consistently avoided due to their physical or chemical properties. Understanding these characteristics helps you select plants that are much more likely to thrive in areas with high deer populations.
Plant Characteristics That Deter Deer
The primary defenses that perennials employ against deer are based on scent, texture, and inherent toxicity. Many plants contain aromatic compounds, such as volatile oils, that release a strong odor when the foliage is brushed or chewed. Deer possess an acute sense of smell and generally find these pungent, herbal scents repulsive, leading them to pass over the plant entirely. This category includes many popular herbs and ornamental varieties whose strong fragrance serves as an effective, natural repellent.
Physical features also play a large role in a plant’s defense mechanism against browsing animals. Deer are wary of plants with coarse, hairy, or fuzzy leaves, which create an unpleasant mouthfeel. Lamb’s Ear (Stachys byzantina) is a prime example, with its dense, velvety foliage being consistently avoided. Plants with tough, leathery foliage or sharp, spiny edges are difficult to consume and offer little reward for the effort.
Beyond texture and smell, some perennials contain chemical compounds that are either toxic or simply taste bitter, discouraging the deer from taking more than a test bite. This causes the deer to associate the plant with a negative digestive experience. The chemical deterrents ensure that they are low on the deer’s list of preferred forage, especially when other food is readily available.
Specific Perennials Deer Avoid
Many sun-loving perennials are inherently resistant to deer due to their strong aromatic properties. Catmint (Nepeta) is highly effective because its minty, fragrant foliage is strongly disliked by deer, yet the plant is attractive to pollinators. Russian Sage (Perovskia atriplicifolia), a sub-shrub with silvery-gray leaves, possesses a pungent, sage-like aroma that acts as a powerful deterrent. Lavender (Lavandula) is also highly resistant, as its concentrated essential oils make it consistently unappealing.
For late-season color, tough-leaved varieties like Coneflower (Echinacea) and Black-Eyed Susan (Rudbeckia) are excellent choices. Their coarse texture and slightly bitter taste mean deer typically leave the flowers and leaves alone. Peonies (Paeonia) are also rarely bothered, likely due to their tough, thick stems and the presence of mild toxins throughout the plant tissue. These large, showy bloomers offer reliable, long-term resistance.
Shade-tolerant perennials offer many deer-resistant options, often relying on toxicity or rough texture. Bleeding Heart (Dicentra spectabilis) is rarely browsed because all parts of the plant contain isoquinoline alkaloids, which are toxic if ingested. Brunnera macrophylla deters deer with its coarse, sandpaper-like leaf texture, which is highly unappealing. Ferns, such as the Japanese Painted Fern (Athyrium niponicum), are also good choices, as their fronds are low in nutritional value and possess a tough, fibrous structure.
Ornamental grasses are a final group of perennials that deer typically ignore because they offer little nutritional value compared to broadleaf plants. Varieties like Switchgrass (Panicum virgatum) and Feather Reed Grass (Calamagrostis) have tough, fibrous blades and are difficult for deer to digest. These grasses provide structure and movement in the landscape.
Factors Influencing Deer Feeding Habits
The effectiveness of any deer-resistant plant is not absolute, as external factors heavily influence a deer’s feeding choices. Regional deer population density is a major variable; high deer numbers force deer to consume plants they would normally avoid due to competition for food. When preferred forage becomes scarce, a deer’s threshold for unpleasant taste or texture lowers considerably.
Seasonal changes in food availability also dictate feeding patterns, particularly during periods of environmental stress. When the natural food supply is critically low, such as in late winter or during a severe summer drought, deer browse even the most resistant garden plants. Drought conditions can cause the deer’s preferred food sources to dry out, making the moisture-rich foliage of garden perennials attractive despite their inherent defenses.
The age of the plant is another factor that can override resistance. Deer often nibble on new, tender growth, regardless of the species, due to its high moisture content and digestibility. Young perennial shoots and emerging buds are softer and less concentrated with defensive compounds than mature foliage. Protecting new plantings is necessary until they establish their full defensive characteristics.