Canna lilies, known for their large, tropical foliage and vibrant blooms, are a popular choice for adding dramatic summer color to gardens. For gardeners in areas with significant wildlife pressure, the question of whether these plants can survive deer browsing is a major concern. Understanding the plant’s inherent defenses and the variables that can compromise them provides the definitive answer to Canna’s standing in a deer-prone landscape.
Canna’s Natural Deer Resistance
Canna lilies (Canna spp.) are recognized as a deer-resistant plant, meaning they are seldom severely damaged by browsing. This classification is due to specific physical and chemical properties that deer find unappealing. The large, paddle-shaped leaves develop a tough, fibrous, and leathery texture as they mature, making them physically difficult for deer to chew and digest.
The plant also possesses an internal deterrent in its flavor profile. Deer generally avoid Canna lilies because their foliage and rhizomes have a bitter taste. This bitterness signals to the deer that the plant is an undesirable food source, causing them to choose easier alternatives. This combination of tough texture and bitter flavor makes the Canna lily a low-preference food item.
Factors Influencing Deer Consumption
The term “deer-resistant” does not mean “deer-proof,” and external pressures can override a deer’s natural aversion to Canna lilies. The primary factor is the scarcity of preferred food sources, often occurring during periods of drought, deep snow cover, or late winter. When their typical diet is unavailable, deer become less selective and will consume plants they would otherwise ignore.
Another variable is the local deer population density. In areas with high browsing pressure, competition for food forces deer to explore non-preferred plants, increasing the likelihood they will sample Canna foliage. Deer are also naturally curious and may sample a novel plant to test its palatability, which can lead to light browsing damage.
New Canna growth is particularly vulnerable to damage, as the young shoots are softer and less fibrous than mature foliage. High nitrogen levels in fertilized soil can also make the new growth more attractive, creating a temporary saltiness that can tempt a hungry deer. This early-season browsing can cause significant damage before the plant establishes its full defenses.
Practical Strategies for Deterrence
For gardeners whose Canna lilies are being browsed, implementing active deterrence strategies offers necessary protection. Physical barriers are the most reliable method, with a permanent fence of at least seven to eight feet being effective at excluding deer. For smaller plantings, temporary plastic netting or wire cages around individual plants can prevent direct access to tender new growth.
Chemical deterrents work by mimicking the smell or taste of predators or rotten food, making the foliage unappetizing. Commercial repellent sprays containing ingredients like rotten eggs or capsaicin must be reapplied regularly, especially after rain or as new growth emerges. Rotating the type of repellent used every few weeks prevents deer from habituating to a single scent or taste.
Strategic planting, or companion planting, can also create an effective buffer around Canna lilies. Placing Canna near highly aromatic plants, such as alliums, lavender, or rosemary, can mask the Canna’s scent and deter deer. The presence of plants with fuzzy or prickly foliage, which deer dislike, can further discourage browsing near the Canna plants.