Boxwood (genus Buxus) is a popular evergreen shrub frequently utilized in landscaping across North America for hedges, borders, and topiary. Valued for its dense foliage and ability to hold a manicured shape, boxwood is a fixture in many gardens and public spaces. Despite its ornamental appeal, all parts of the plant contain compounds that are toxic to humans and pets if ingested. Understanding these risks is important for homeowners and gardeners.
The Toxic Components
The toxicity of boxwood is due to steroidal alkaloids present within its tissues. The primary toxic agent is a bitter alkaloid known as Buxine. These compounds are not evenly distributed, with the highest concentrations typically found in the leaves and the bark. The sap also contains these alkaloids and can cause a reaction upon contact.
When consumed, Buxine acts primarily as a strong irritant to the gastrointestinal tract. In larger doses, these alkaloids have the potential to affect the nervous system. The entire boxwood plant, including the roots and stems, should be considered poisonous.
Symptoms of Human Exposure
Ingestion of boxwood most commonly results in a range of gastrointestinal symptoms. Within a short period, a person may experience nausea and severe abdominal cramping. This often progresses to vomiting and diarrhea, as the body attempts to expel the irritating toxins. These symptoms are usually the first indicators of accidental consumption, particularly in children.
More serious effects are possible, though rare, and typically linked to consuming a significant amount of plant material. In these cases, the alkaloids can produce nervous system disturbances, including dizziness or lightheadedness. Extremely large doses may lead to severe complications such as convulsions, seizures, and respiratory failure. Beyond ingestion, direct handling of the boxwood plant, especially the sap or foliage, can result in mild contact dermatitis, manifesting as skin irritation, redness, and a rash on the affected area.
Immediate Steps After Exposure
If boxwood ingestion is suspected, the immediate action is to contact Poison Control for expert guidance. The national hotline (1-800-222-1222) is available 24 hours a day and provides free, case-specific advice. It is important to have specific details ready for the operator, including the approximate amount of plant material consumed, the time of ingestion, and the age and weight of the affected person.
Do not attempt to induce vomiting or give the person anything to eat or drink unless specifically instructed by Poison Control or a medical professional. For instances of skin exposure, the affected area should be thoroughly washed with soap and water to remove any irritating sap. If the person shows severe symptoms, such as difficulty breathing, seizures, or loss of consciousness, seek emergency medical care right away.