One way plants protect themselves from being eaten by animals is generating toxic chemicals in leaves, blooms or fruits. Some plants are so well known for this characteristic that their names contain a warning; deadly nightshade is an example. More often, however, a plant name gives no clues. Parents of young children and pet owners can make their yards and homes safer by consulting lists of poisonous plants and assessing danger accordingly. Geraniums provide a good illustration of how to proceed.
Geranium Protective Mechanisms
Geraniums contain an essential oil, geraniol, which can produce an allergic contact dermatitis in both people and animals. The same irritant qualities probably account for the varieties of geranium that score high on deer-resistant scales.
Symptoms of Geranium Toxicity
Irritant oils can produce swelling, rashes and blistering. Clearly, if eaten by animals or young children, delicate mouth, throat and digestive tract tissues can suffer from the exposure.
Response to Symptoms
While wild animals may generally avoid the unpleasant taste and irritant oils in geraniums, pet owners who suspect that curious dogs or cats have eaten geranium should contact their veterinarians for help. The ASPCA also maintains a list of plants toxic to pets online.
ASPCA Balanced View
In a recent ASPCA interview, published in the Albuquerque Journal, veterinarian Tina Wismer addresses the issue pet owners find most troubling when dealing with pets and plants: How toxic is toxic. Wismer points out that both the flavor and irritant qualities of geranium leaves deter her pets, and will probably deter most pets, from eating enough geranium to cause severe illness.
Managing Plants and Pets
Some concerns about pets and plants can be managed physically, by placing potentially toxic plants where they are hard for pets to reach. Hanging baskets, plant stands or tall containers can make access harder for curious cats and dogs. In ground-level plantings, consider putting down diatomaceous earth, low fencing or commercial underfoot pet-repellents to make approaching plants unpleasant or difficult. Sweep up plant debris regularly.