Petunias are popular annual flowers, favored by gardeners for their continuous blooms and vibrant color range. When considering resistance to wildlife, petunias are categorized as “resistant” rather than “proof” against common garden pests like deer and rabbits. This means the plants are low on the animals’ preferred menu, but they will be consumed if an animal is hungry or other food sources are scarce. The likelihood of damage often depends on local environmental conditions and the population density of the herbivores.
The Petunia’s Natural Defense Mechanisms
The inherent resistance of petunias stems from two distinct botanical features that make them unappealing to browse. The most visible defense is the presence of sticky, glandular hairs, known as trichomes, which cover the stems and foliage. These microscopic structures create an unpleasant texture, physically deterring animals.
These trichomes also act as delivery systems for defensive chemical compounds synthesized by the plant. Petunias produce secondary metabolites, such as the steroidal compounds petuniasterone and petuniolide, which are deterrent to many generalist herbivores. This chemical defense contributes to the pungent scent and bitter taste that makes the foliage unpalatable to deer and rabbits. The combination of a sticky texture and an off-putting taste establishes the plant’s baseline resistance.
Deer Feeding Habits and Petunias
Deer are opportunistic browsers that typically feed at a higher level than rabbits and are drawn to plants with a soft, moist texture. Petunias are relatively soft and succulent, leading some agricultural extensions to rate them as “Occasionally Severely Damaged.” Deer often test the plant by sampling the most tender parts first, usually the newly formed flower buds and open blossoms.
Destruction of petunias by deer most often occurs under duress, such as during late winter, severe drought, or when local deer populations are high. These conditions limit the availability of their preferred forage, pushing them to consume less-palatable plants. Deer typically browse by pulling and tearing plant material, resulting in a ragged, torn appearance on the remaining stems and foliage. When food is extremely limited, deer will consume the entire plant.
Rabbit Feeding Habits and Petunias
Rabbits are ground-level feeders that prefer young, tender growth. They are more likely to eat petunias that are newly transplanted or those with soft stems and leaves. Rabbits are recognized for their distinct method of feeding, which involves cleanly clipping the stem at a 45-degree angle using their sharp incisor teeth.
Damage from rabbits is typically confined to the lowest 18 to 24 inches of the plant, often near the base or on trailing varieties. They are also more likely to feed close to protective cover, such as dense shrubs or woodpiles. If a rabbit’s primary food source, like clover or tender lawn grasses, becomes unavailable, the petunia’s soft leaves become a more attractive alternative despite the natural chemical deterrents.
Protecting Petunias and Alternative Choices
Gardeners dealing with persistent petunia damage can employ a strategy involving physical protection and the use of repellents. Placing petunias in hanging baskets or tall, raised planters elevates them out of the reach of rabbits and makes them less convenient targets for deer. For ground plantings, a low physical barrier of chicken wire or hardware cloth, buried a few inches into the soil and standing at least two feet high, can effectively exclude rabbits.
Repellent sprays offer another layer of defense and are categorized as taste-based or scent-based. Taste-based products often contain ingredients like putrescent egg solids or capsaicin (hot pepper), which must be applied directly to the foliage. Scent-based options, such as those utilizing predator urine or strong soaps, create an odor barrier that suggests danger. Repellents must be reapplied frequently, especially after rain or new plant growth, and rotating between different types prevents the animals from acclimating.
For areas with high pressure from deer and rabbits, selecting highly resistant annuals may be a more practical approach. These alternatives allow gardeners to maintain a colorful display without the constant worry of browsing.
Highly Resistant Annual Alternatives
- Lantana, which has rough, pungent foliage.
- Marigolds, known for their strong aroma.
- Zinnias, which are seldom damaged.
- Geraniums, which are also seldom damaged.