The iris, celebrated for its striking blooms and varied colors, is a popular perennial in many gardens. Gardeners often ask whether deer eat these flowers. Irises are broadly considered deer-resistant, but no plant is completely deer-proof. Deer typically avoid them due to natural defenses, but they may browse them under specific conditions.
Understanding Iris Resistance
The primary reason deer bypass most iris varieties is the plant’s natural defense mechanism, which includes an unpalatable taste and a tough texture. Iris foliage, particularly the stiff, sword-like leaves of types like Siberian and Japanese irises, is fibrous and difficult for deer to chew. This texture offers little nutritional reward compared to softer, more succulent plants.
Irises also contain chemical compounds that act as internal deterrents. Many species possess a bitter taste and a strong, pungent fragrance that deer find offensive. Some varieties contain mildly toxic components, such as the alkaloid lycorine, which can cause digestive upset if consumed in significant quantities.
The combination of unpleasant odor, bitter flavor, and tough foliage usually causes deer to sample an iris and quickly move on. This inherent resistance is why irises generally receive a “rarely damaged” rating regarding deer browsing. Deer will not choose irises unless their foraging options become severely limited.
When Deer Ignore Natural Deterrents
A deer’s feeding habits can change drastically in response to environmental pressures. Extreme food scarcity often overrides a deer’s natural aversion. During harsh winters or severe droughts, when preferred food sources are unavailable, deer may resort to browsing less desirable plants, including irises, simply to survive.
Young plants and new growth are more vulnerable than established foliage. Tender new shoots emerging in the spring are softer and contain higher moisture content, making them more appealing before the leaves harden. Fawns, still learning, may also take exploratory samples.
The location of the plant can also influence browsing. Irises planted along a frequently traveled deer path or in easily accessible areas are more likely to be tested. The plant’s defenses are effective as a deterrent, but they are not an absolute barrier against a hungry animal.
Protecting Iris Plants from Browsing
Gardeners can employ strategies to supplement the iris’s natural resistance and minimize browsing damage. Physical barriers, such as temporary or permanent fencing, provide the most reliable exclusion method. A seven-foot fence is generally required to prevent deer from jumping, but smaller netting can protect young plants during establishment.
The application of deer repellents is effective, working either by taste or scent. Taste-based repellents (e.g., putrescent egg solids) are applied directly to the foliage to make the plant unappetizing. Scent-based products (e.g., garlic or mint) deter deer from the area. Repellents must be reapplied regularly, especially after rain.
Strategic planting can also offer protection. Placing irises closer to the house or in highly visible areas can deter deer, as they are wary of human activity. Companion planting involves placing irises near other highly scented, unpalatable plants, such as alliums or lavender, whose strong odors may discourage browsing.