Siberian Iris (Iris sibirica) is a popular, hardy perennial prized for its delicate blooms and tough, grass-like foliage. Gardeners often seek to confirm its resilience against local wildlife, especially in areas with high deer populations. Determining the plant’s palatability helps homeowners select plants that can thrive without constant intervention.
The Deer Resistance Status of Siberian Iris
The Siberian Iris is considered a highly deer-resistant plant, meaning deer rarely consume it. This natural defense is rooted in the plant’s physical and chemical composition. The leaves and stems are fibrous and tough, providing an unappealing texture that deer generally avoid when softer forage is available.
Beyond texture, the plant contains compounds that make it unpalatable or mildly toxic. Iris species possess an unidentified toxic principle, possibly a glycoside, which can cause mild stomach upset. This bitterness and potential for gastrointestinal distress act as a deterrent, placing the Siberian Iris in the “rarely damaged” category on deer resistance rating scales.
Factors Influencing Deer Consumption
Although Siberian Iris is naturally resistant, no plant is entirely deer-proof. Environmental factors can override a deer’s natural aversion, primarily extreme food scarcity during severe winter weather or prolonged drought. Under these conditions, a starving deer will sample nearly any vegetation to survive.
Young deer, or fawns, sometimes sample foliage out of curiosity while learning their dietary preferences. Newly installed Siberian Iris plants may also be more vulnerable because they are often tender from nursery cultivation. High localized deer density can also increase browsing pressure, forcing animals to graze on less desirable plants.
Protecting Your Iris
For gardeners who experience browsing, several strategies can provide an added layer of protection. Physical barriers, such as temporary wire cages or netting, are highly effective for new plantings, ensuring they establish a strong root system. Commercial deer repellents utilize two main modes of action: taste and odor.
Odor-based repellents, often containing putrescent egg solids, create a fear response by mimicking the smell of a predator or decay. Taste-based repellents, like those containing capsaicin or bittering agents, must be consumed to be effective but quickly teach the deer that the plant is undesirable. Planting the iris alongside highly aromatic companion plants, such as lavender or allium, can also help mask the iris’s scent.