Foxglove are eye-catching flowering plants that can be grown in USDA plant hardiness zones 4 through. Most varieties are biennials that live for only two growing seasons, but some species can survive as perennials in some climates. Foxglove plants are among the most poisonous plants commonly grown in home landscapes. Do not grow them if small children will be spending time in your yard.
Taxonomy and Botany of Foxglove Plants
Plant taxonomy classifies the most commonly grown foxglove plants as Digitalis purpurea. Most types of foxglove plants are grouped with the biennials in the field of botany. The first year, the plant has leaves that form a rosette close to the ground. The second (and final) year, it develops a spike with blooms. However, under the right growing conditions, foxglove often last longer, blooming another year or two beyond what their "biennial" status would warrant. In this case, they may be considered herbaceous perennials. The most reliably perennial species is Digitalis grandiflora.
Further complicating any positive life-cycle identification for the novice is the fact that foxglove plants often reseed themselves. As a result, what appears to be the same plant coming up again from last year may actually be a seedling from the original plant.
Other types of foxglove include:
- 'Goldcrest,' which has yellow blooms
- D. obscura, which has orange flowers
- 'Candy Mountain,' with bright, rosy-pink flowers that face upwards rather than nodding down
- D. grandiflora, with large yellow flowers
- D. x mertonensis, a hybrid plant of D. purpurea and D. grandiflora with very large, coppery-pink blossoms
Characteristics of Foxglove
Foxglove are tall, slender plants that grow 2 to 5 feet tall and just 1 to 2 feet wide. Their blooms include multiple tubular, often freckled, flowers that form on a spike. They are usually nodding flowers that range in color from purple to white. The white ones can be used in moon gardens. Bloom time is in the early summer months (late spring in warm zones). Most foxglove, being biennial, do not produce flowers in their first year.
Grow foxglove plants in full sun, partial sun, or partial shade in a fertile, well-drained, acidic soil. Once mature, they tolerate dry shade but not full shade. Apply a 3-inch layer of mulch for winter protection if your region is borderline zone 4. Tailor the amount of sunshine you give this biennial to your climate. If you live in the South, give it some shade. In the North, you can grow it in a range of sunlight conditions, from full sun to partial shade, although it will perform best in partial sun.
Foxglove Uses in Landscaping
Because of their height, foxglove plants are good for the back row of a flower border. These tall specimens are also considered classic plants for cottage gardens. They are among the flowers that attract hummingbirds.
Foxglove are susceptible to crown rot, so provide them with good drainage. Powdery mildew disease and leaf spot are other problems that can affect foxglove plants. Try to provide good air circulation by giving them sufficient spacing. Foxgloves come in different sizes and should be spaced accordingly, but as a general rule, it is good to space them about 2 feet apart. Stake the taller types to prevent them from flopping over in a wind storm. Do not deadhead these biennials if you want them to reseed for you.
As with many poisonous plants, foxglove has been used traditionally by expert herbalists for medicinal purposes. Even today, drugs made from Digitalis are used to strengthen the heart and regulate heartbeat.
Origin of the Foxglove Name
According to the University of Arkansas Cooperative Extension (UACE), the common name "foxglove" derives from the old English "foxes glofa" and stems from ancient lore claiming "that foxes must have used the flowers to magically sheath their paws as they stealthily made their nocturnal raids into the poultry yards of rural folk."
Further explaining the connection, UACE notes that the flowers naturally grew on the wooded hillsides where foxes made their dens. This flower has inspired other cute common names over the centuries, including "witches' gloves" and "fairy caps."
The scientific genus name Digitalis refers to the fact that foxglove flowers are just about the right size for slipping your fingers into, as the Latin translation of digitalis is "measuring a finger's breadth." It is easy to remember this name origin, since we sometimes refer to our fingers as "digits."