Bearded irises are a popular, hardy garden staple, prized for their vibrant, showy blooms and ability to thrive in various climates. For many gardeners, the presence of deer dictates which plants can be successfully grown and enjoyed. This browsing pressure makes a plant’s palatability a major concern for landscape planning. Fortunately, bearded irises possess natural defenses that generally make them unappealing to these foraging animals, providing a reliable choice for gardens in high-deer areas.
The Bearded Iris Resistance Rating
Bearded irises are classified as deer-resistant, meaning they are not a preferred food source. Many agricultural extension programs, including the Rutgers University scale, rate irises as “rarely damaged” by deer. This designation indicates that deer seldom browse the plants, doing so only under extreme circumstances. The tough, stiff, sword-like foliage is not physically attractive for deer to chew, contributing to its low-preference rating. No plant is truly “deer-proof,” but irises remain a low-risk option.
The Chemical Reason for Avoidance
The primary mechanism behind the bearded iris’s avoidance rating is the presence of unpalatable and toxic compounds throughout its structure. These plants contain a group of chemicals known as glycosides. When ingested, these compounds are responsible for causing significant digestive upset in animals. The highest concentration of these toxic principles is found within the plant’s thick, nutrient-storing rhizomes. Consumption leads to symptoms such as profuse salivation, vomiting, and diarrhea, acting as a powerful deterrent that teaches deer to avoid the plant.
Situations When Deer Might Still Feed
Despite their strong natural defenses, irises may show signs of browsing under certain conditions. Deer are most likely to sample or feed on irises during periods of intense environmental stress or food scarcity. A severe drought or a harsh winter reduces the availability of preferred natural forage, forcing deer to try less appealing plants. Juvenile or inexperienced deer may also cause minor damage while learning which plants to avoid. This browsing is limited to the tender new shoots or flower buds, but the robust plant is tough enough to recover quickly.
Protecting Your Garden from Deer
While bearded irises are resistant, homeowners experiencing sustained deer pressure should employ layered deterrent strategies for total garden protection.
Physical Barriers
Physical barriers are the most reliable method. A permanent fence should be at least eight feet high to prevent deer from jumping over it. For a less intrusive option, a solid-panel fence of six feet is effective, as deer are hesitant to jump when they cannot see the landing area.
Chemical Deterrents
Scent and taste deterrents provide another effective layer of defense, including both commercial and homemade solutions. Commercial sprays often contain putrefied egg solids that adhere to the foliage, creating a repulsive odor and taste. Homemade applications, such as a mixture of liquid dish soap, hot sauce, and water, can also be sprayed directly onto plants to make them unappetizing. Remember to rotate deterrent types and reapply them frequently, especially after rain, to prevent deer from becoming accustomed to a single method.