Foxglove is Pretty, but Causes Reactions in Humans and Animals

Tall spikes with flowers are pretty but toxic

By Nicole Hook
Foxglove plants grow in tall spikes with flowers of varying colors. They are pretty but toxic to humans and animals. Photo: PublicDomainPictures.net

Foxglove is a pretty plant, with tall flowering spikes of colors in purple, pink, yellow, or white. People consider them pretty and like to pick them or have them in their gardens. But their appearance is deceptive in that the plants are actually very toxic, to both people and animals.

I learned about the properties of this plant because I had thought about planting some at my old house, but where I have cattle I look things up before I plant it. After learning about its dangers, I was disappointed to find it here at this house in Andover. It is hard to get rid of and is considered an invasive weed in many states. It has been referred to as an agricultural weed in New Hampshire.

There have been occasions where some people pick it, as the flowers are pretty, not realizing what it is, and the unfortunate end up in a hospital emergency room. It is usually limited to gardens in this area of New Hampshire, but it sometimes can be found on old homesteads, where it was grown for digitalis. It spreads by itself, as it self-seeds. So beware, and watch out for the plant with pretty flowers and a cool name. It’s poison.

From my research, I learned that toxins can get on the hands from handling and crushing the plant, and then transferred to the eyes and mouth, and absorbed through open cuts on the hands. If too much toxin from the plant is absorbed or ingested, it can cause many unpleasant or dangerous side effects, including nausea, skin irritation, headache, diarrhea, small eye pupils, blurred vision, strong slow pulse, vomiting, dizziness, excessive urination, fatigue, muscle weakness, tremors, stupor, confusion, convulsion, abnormal heart beat, low blood pressure, and, although rare, death. Most people who have a bad reaction are still able to get medical help.

For some background, found in the Encyclopedia Britannica, the plant is native to Europe, the Mediterranean, and the Canary Islands. It flowers from June to September, although some varieties don’t grow flowers. The spikes can grow from 18 to 60 inches tall. Each plant can produce 1 to 2 million seeds. 

All parts of the foxglove plant are toxic to animals and people. Even inhaling the pollen can cause an adverse reaction in some people. The leaves have fine hairs that can cause a rash that can last for two to three weeks. The plant contains digitalis (hence the botanical name Digitalis purpurea) and other cardiac glycosides which are used in medicine in very small doses.

Also from the Encyclopedia Britannica, and library.uthscsa.edu, doctors in England, most notably William Withering, started experimenting with the use of foxglove around 1776 to treat dropsy or edema (fluid build up in the body – congestive heart failure), irregular heartbeat, and heart failure. Digitalis is used to slow heart rate and strengthen contractions of the heart muscle. It also increases heart output and decreases the size of the heart. It is only used in very small doses because half a gram of dried leaf or two grams of fresh leaf ingested is enough to kill an adult human.

In spite of the possible dangers of handling and/or being around Foxglove, it can still be found for sale at garden shops and nurseries in New Hampshire. Bedford Fields, in Bedford, advertises this plant for use in gardens. The only special consideration listed (plants.bedfordfields.com/12120032/Plant/4567/Common_Foxglove) is that it is “Self-Seeding,” but it does state that “…parts of it are known to be toxic to humans and animals, so care should be exercised in planting it around children and pets.”

So, for anyone in Andover with kids or animals, I’d suggest becoming familiar with this plant, especially before adding it to gardens, or picking it in fields. If you still wish to add it to your garden because it’s pretty, you can find more information from the UNH extension (extension.unh.edu), or from other gardening websites.