Irises are celebrated in home gardens for their vibrant blooms and simple care requirements. However, they are not immune to local wildlife, and damage to foliage or the sudden disappearance of flowers can be frustrating. Determining the specific animal responsible is the first step toward effective protection. Identifying whether the culprit feeds above or below the soil line helps select an appropriate defense.
Mammals and Rodents That Target Irises
Animals that target irises are divided into above-ground feeders, which consume tender parts, and subterranean pests, which attack the rhizomes. Above-ground feeders primarily include deer and rabbits, which eat foliage, buds, and flowers. Deer occasionally graze on iris leaves and developing flower stalks, especially when natural forage is scarce. Rabbits commonly target the leaves and stems, focusing on tender new growth emerging in late winter or early spring.
Subterranean pests focus their feeding on the iris rhizome, the underground storage organ. Voles, small mouse-like rodents, chew on the fleshy rhizomes and bulbs. As they tunnel through the soil, voles cause extensive damage by consuming the plant’s energy source. Gophers are another threat, capable of eating entire root systems and pulling whole plants into their underground tunnels.
Recognizing Specific Damage Patterns
Identifying the exact pest requires examining the damage, as different animals leave distinct feeding signatures. Deer lack upper incisors, causing them to bite down and pull, which results in a ragged, torn, or frayed appearance on stems and leaves. Deer damage is often found higher on the plant, sometimes leaving a noticeable browse line. They may also completely uproot a young plant while tearing off a bite.
Rabbit damage is distinguishable by clean, sharp, angled cuts, appearing as though the plant was snipped with shears. Rabbits possess sharp incisors that allow them to make a precise cut, typically close to the ground at the base of the stems. If the entire fan of leaves is missing, leaving a clean stump just above the soil, a rabbit is the likely culprit. This distinction between a ragged tear (deer) and a clean slice (rabbit) is the most reliable way to differentiate their feeding.
Damage from voles appears as irregular chew marks on the rhizomes, often exposed when a damaged plant is lifted. Voles create small, inconspicuous entrance holes and shallow, above-ground runways as they travel between feeding sites. Gopher activity, in contrast, results in the complete disappearance of the plant, which is dragged down into the tunnel system. Gophers also leave distinct fan-shaped mounds of soil, where the tunnel entrance is plugged and offset to one side.
Effective Deterrence Strategies
Protecting irises requires strategies tailored to the animal’s specific feeding habits. For deer, physical barriers are the most reliable defense, though a fence must be at least eight feet tall to be effective. Repellents containing ingredients like putrescent egg solids can deter deer and rabbits through taste and smell, but they require reapplication after rain. These repellents are most effective when applied to new growth before the animals establish a feeding habit.
To protect against rabbits, use a short fence of chicken wire or hardware cloth around the iris beds, ensuring it is at least two feet tall and secured to the ground. Subterranean pests like voles and gophers require underground defenses to shield the rhizomes. Planting irises in individual wire baskets constructed from one-quarter inch galvanized hardware cloth is an effective physical barrier. This mesh prevents rodents from reaching the rhizome while allowing roots to grow into the surrounding soil. The baskets should be wide enough for rhizome growth, but only five to eight inches deep, covering the plant’s underground parts.