Foxglove, a striking plant belonging to the Digitalis genus, is a popular choice for ornamental gardens worldwide. Known for its tall, spire-like stalks covered in bell-shaped blooms, it adds a distinct vertical element to borders and cottage garden designs. Gardeners often seek out this plant for its aesthetic appeal, and those gardening in areas with high wildlife activity often wonder if Digitalis plants are resistant to deer.
Why Deer Avoid Foxglove
The plant’s reputation as a deer-resistant species lies in its natural chemical defenses. Foxglove produces powerful compounds known as cardiac glycosides, which deter most herbivores. These toxic substances, including digoxin and digitoxin, are present in all parts of the plant: the leaves, stems, flowers, and seeds.
When ingested, these glycosides interfere with the sodium-potassium pump mechanism in animal cells, severely disrupting heart function and the central nervous system. The bitterness provides an immediate, unpleasant taste cue that signals danger. Deer and other wildlife quickly learn to avoid plants with such defense mechanisms.
This defense mechanism is effective, leading major agricultural institutions to rate the plant as “rarely damaged” by deer. The concentration in the raw plant material is highly toxic and can cause irregular heart rhythms, vomiting, and sudden death in animals. Foxglove’s potent chemistry ensures that deer typically pass it over in favor of more palatable forage.
Factors Affecting Deer Resistance
While foxglove is widely recognized as resistant, no plant is entirely “deer-proof.” Resistance levels fluctuate based on environmental and population factors. Deer are inquisitive feeders, and young or newly planted specimens may occasionally be sampled out of curiosity before the animal recognizes the taste.
The availability of other food sources is the largest factor that can override a deer’s natural aversion. During periods of extreme scarcity, such as severe winter weather or prolonged drought, a starving deer may browse on almost any plant, including toxic species. High population density also increases browsing pressure, making it more likely for deer to test less desirable options.
Gardeners in high-pressure zones can take steps to protect new or vulnerable plantings. Placing temporary physical barriers, such as wire cages, around young plants helps them establish a robust root system. Incorporating foxglove into a layered planting scheme, surrounded by other strongly scented or prickly deer-resistant plants, also reduces the likelihood of browsing.
Safe Handling of Foxglove in the Garden
The powerful toxins that deter deer necessitate careful handling by human gardeners. All parts of the foxglove plant, including the leaves, flowers, seeds, and vase water, contain cardiac glycosides that are poisonous if ingested. The leaves can be easily mistaken for edible greens like comfrey, posing a serious risk if the plant is situated near a vegetable garden.
Gardeners should wear gloves when handling Digitalis plants, especially when pruning, deadheading, or pulling up old stalks. Although the plant is not poisonous to the touch, trace amounts of toxins can be absorbed through contact with sap or broken skin. This precaution minimizes the risk of accidental transfer to the mouth, eyes, or other sensitive areas.
Homeowners with pets or small children must exercise caution, as accidental ingestion can lead to severe poisoning. The toxins remain potent even when dried, meaning clippings should never be added to compost piles. All discarded foxglove material should be bagged and disposed of with household waste to prevent risk to curious animals or children.