Ornamental grasses are perennial plants valued for the texture, structure, and movement they bring to landscapes. People frequently ask if these plants can withstand browsing pressure from local wildlife. The answer is generally yes; most ornamental grasses possess a high degree of natural resistance to deer. However, this resistance is not absolute, and palatability can vary based on the species and surrounding environmental conditions.
Why Deer Typically Avoid Ornamental Grasses
The primary mechanism that deters deer from consuming most ornamental grasses is the presence of silica within the plant tissue. Grasses, belonging to the family Poaceae, deposit microscopic silica bodies called phytoliths in their leaves and stems. This mineral content gives the foliage a tough, abrasive texture that is difficult for deer to chew and digest.
The high silica content acts like tiny shards of glass, which can irritate the delicate lining of a deer’s mouth and wear down their teeth. Deer instinctively seek soft, high-moisture forage for easy consumption and nutrition. The fibrous, coarse structure of mature ornamental grass blades offers little nutritional reward for the effort required to process them. This abrasive texture and low palatability make most ornamental grasses an unappealing food source.
Reliably Resistant Ornamental Grass Species
Certain genera of ornamental grasses are noted for their robust resistance to deer browsing. These species tend to have exceptionally tough foliage, making them a safe choice for gardens in areas with high deer activity.
Miscanthus sinensis, commonly known as Maiden Grass, is one of the most reliable choices for deer resistance. Its tall, dense habit and sharp-edged blades are rarely sampled by deer, offering year-round structure. Popular cultivars include ‘Morning Light’ and ‘Gracillimus’, valued for their fine texture and upright growth.
Another highly resistant group is Calamagrostis or Feather Reed Grass, exemplified by the hybrid ‘Karl Foerster’. This grass maintains a vertical, stiff structure that deer typically ignore. Its long-lasting, feathery plumes emerge early in the season, and the tough foliage discourages browsing.
Native grasses like Panicum virgatum, or Switchgrass, also exhibit strong resistance. Cultivars such as ‘Heavy Metal’ and ‘Shenandoah’ feature upright, rigid stems and naturally abrasive foliage. Their deep root systems contribute to resilience against environmental stress and animal damage. Other dependable native options include Schizachyrium scoparium (Little Bluestem) and Chasmanthium latifolium (Northern Sea Oats).
Vulnerable Grasses and Environmental Factors
While the majority of ornamental grasses are avoided by deer, exceptions exist, often involving varieties with softer, less fibrous foliage. Certain cultivars of Pennisetum (Fountain Grass), particularly those with fine or delicate blades, may be more vulnerable to sampling. Although many Fountain Grass varieties are resistant, deer are sometimes known to nibble the softer, newer growth or the fluffy seed heads.
A plant’s natural resistance is secondary to a deer’s need for survival, and environmental factors can override natural defenses. During periods of severe environmental stress, deer are forced to expand their diet to whatever is available. Extreme hunger, often occurring in late winter or early spring when fat reserves are depleted, can prompt them to consume less-palatable plants.
Drought conditions or the presence of an unusually high deer population can lead to the browsing of typically avoided ornamental grasses. When preferred food sources are exhausted, deer will sample plants they usually ignore, including silica-rich foliage. This desperation browsing means no ornamental grass is absolutely deer-proof, though their inherent toughness makes them a last resort for hungry animals.