The Bleeding Heart (Lamprocapnos spectabilis or Dicentra spectabilis) is a popular addition to many shade gardens, admired for its unique, heart-shaped flowers. Gardeners frequently worry about the plant’s appeal to common garden herbivores, specifically rabbits. This concern is often compounded by questions regarding the plant’s safety, as many pests are deterred by compounds that make plants unsafe for consumption. The plant possesses a chemical defense system that makes it a less-than-ideal food source for most animals.
Palatability and Avoidance
Bleeding Hearts are generally classified as rabbit-resistant due to their inherent unpalatability. Rabbits rely on their sense of smell and taste to identify safe food sources, avoiding plants with strong scents or bitter tastes. The leaves and stems of the Bleeding Heart contain bitter-tasting compounds, which are a natural deterrent that prompts rabbits to move on after a brief exploratory nibble.
This defense mechanism places the plant on the lower-risk end of a rabbit’s potential menu. However, no plant is completely rabbit-proof, especially when food is scarce, such as during late winter or drought. A hungry rabbit may occasionally sample the foliage, but the unpleasant flavor and resulting mild digestive upset usually prevent significant damage. Rabbits quickly learn which plants cause discomfort and subsequently avoid them.
Understanding the Toxicity Profile
The Bleeding Heart’s resistance to grazing is due to toxic chemical compounds present in all parts of the plant, including the roots, foliage, and flowers. These compounds are isoquinoline alkaloids, such as protopine, sanguinarine, and chelerythrine, which are responsible for the plant’s poisonous properties.
When ingested in large quantities, these compounds can cause adverse effects in animals and humans. For rabbits, the immediate reaction is often gastrointestinal distress, which serves as a warning to stop eating. In more severe cases, especially in pets like dogs or horses consuming larger amounts, neurological effects can manifest. Symptoms of significant ingestion include trembling, staggering, vomiting, diarrhea, and convulsions. The sap of the plant can also cause skin irritation or contact dermatitis upon repeated contact.
General Rabbit Deterrence Strategies
Although Bleeding Hearts are generally avoided by rabbits, other vulnerable plants in the garden may still require protection. Installing a physical barrier is one of the most effective methods for general rabbit control. A fence constructed from chicken wire or hardware cloth with a mesh size of one inch or smaller should be at least two feet high.
To prevent rabbits from digging underneath, the fencing material should be buried approximately six inches below the soil surface. Gardeners can also employ commercial or homemade repellents that target a rabbit’s sense of smell or taste. Repellents based on strong scents, such as capsaicin (hot pepper), garlic, or predator urine, can be sprayed directly onto non-edible plants or applied around the garden perimeter. For long-term control, removing potential hiding spots, such as brush piles and tall weeds near the garden, can make the area less appealing for rabbits to inhabit.