Imagine a flower that can both heal the heart and enchant the eye. That is the magic of Digitalis, commonly known as foxglove. This captivating genus of flowering plants brings drama and old-world charm to any garden with its towering spires and bell-shaped blooms. While the iconic purple foxglove ( Digitalis purpurea) might be the most familiar sight, the genus encompasses a diverse array of species and cultivars, each with its unique characteristics. This guide delves into the fascinating world of Digitalis, exploring its distinctive features, native habitat, landscaping uses, and essential planting and care tips for gardeners.

Description and Details Digitalis plants typically feature alternating, ovate to oblong leaves that cluster towards the lower part of the stem. These leaves have prominent veins, giving them an almost quilted look, especially in the first year of growth when the plant forms a tight rosette close to the ground. From this rosette emerges a tall, elegant flower spike, reaching heights of 3 to 4 feet, sometimes even taller. The flower spike is adorned with numerous pendulous, bell-shaped flowers, each about 1½ to 2½ inches long.

These blossoms, which can grow up to 6.5 cm (2.5 inches) long, come in a variety of colors, including shades of purple, pink, white, yellow, and even apricot. The flowers often have distinctive speckles or spots on the inside surface, adding to their visual appeal. In the wild form of Digitalis purpurea, the flowers typically appear on one side of the stem, but cultivated forms often have flowers completely encircling the stem.

Digitalis Varieties The most well-known species is Digitalis purpurea, the common foxglove, which boasts numerous hybrids and cultivars with a wide range of colors and forms. To help you explore the diversity of Digitalis, here is a table summarizing some popular varieties:

Other notable Digitalis species include Digitalis ferruginea (Rusty Foxglove) with rusty-brown or yellow flowers, Digitalis grandiflora (Yellow Foxglove) with pale yellow bells, Digitalis lutea (Straw Foxglove) with smaller, pale yellow flowers, and Digitalis × mertonensis (Strawberry Foxglove) with strawberry-pink flowers.

Lifecycle Most commonly grown Digitalis are biennials, meaning they flower in their second year and then die after setting seed. However, it is important to note that the Digitalis genus includes a variety of lifecycles, with some species being perennial or even shrubs. The fruits of Digitalis are dry capsules containing numerous small seeds.

Native Habitat Digitalis purpurea is native to and widespread throughout most of temperate Europe. Its natural range extends to countries like Belgium, France, Germany, Ireland, Norway, Portugal, Spain, and the United Kingdom. It is also found in Morocco in North Africa.

Within its native habitat, Digitalis purpurea thrives in acidic soils and partial sunlight to deep shade. It typically grows in woodland clearings, moorland and heath margins, sea-cliffs, rocky mountain slopes, and hedge banks. The plant readily colonizes disturbed sites, such as recently cleared woodland or areas affected by fire or construction. This makes it a pioneer species, playing a vital role in ecological succession by stabilizing the soil and creating conditions for other plants to establish themselves.

What Makes Digitalis So Special?

Pollinator Magnet In the garden, Digitalis stands out for its attractiveness to pollinators. The tubular shape and vibrant colors of the flowers are particularly appealing to long-tongued bees, such as bumblebees, which play a vital role in their pollination. Penstemon digitalis, for example, is highly valued by native bees, including Mason, Digger, and Leaf-cutter bees.

Interestingly, studies have shown that foxgloves introduced to the Americas have evolved longer flower tubes to accommodate hummingbird pollination. This adaptation not only demonstrates the remarkable evolutionary capacity of Digitalis but also provides valuable insights into how plant-pollinator interactions can drive evolutionary change.

Genetic Diversity Another fascinating aspect of Digitalis is the genetic basis for its diverse flower colors and spotting patterns. In Digitalis purpurea, a combination of six genes (M, m, D, d, W, w) determines the presence and distribution of pigments, resulting in a variety of phenotypes, from white flowers with purple spots to dark purple flowers with no spots. This genetic complexity contributes to the visual appeal and horticultural interest of Digitalis.

Landscaping Design Tips Digitalis is a versatile plant that can be incorporated into various garden settings. Its tall flower spikes make it an excellent choice for adding vertical interest and structure to borders, beds, and woodland gardens. Here are some design tips for using Digitalis in your landscape:

• Consider Height: Tall varieties like 'Excelsior' hybrids create a dramatic backdrop, while shorter varieties like 'Foxy' are suitable for smaller spaces or containers.
• Flower Form: Most Digitalis purpurea have classic downward-facing bell-shaped flowers, while the 'Gloxinioides Group' offers more open and showy blooms.
• Color Combinations: Experiment with different Digitalis colors to create striking combinations. For example, combine white-flowered varieties with deep purple or pink cultivars for a contrasting display.
• Companion Plants: Digitalis pairs well with various companion plants, including roses, ferns, hostas, astilbes, and other shade-loving perennials.
• Mass Plantings: Create a dramatic impact by planting Digitalis in groups of five or more, especially with varieties that offer a mix of colors.
• Woodland Gardens: Utilize Digitalis in woodland settings to add height and color among ferns, hostas, and other shade-tolerant plants.
• Cottage Gardens: Incorporate Digitalis into cottage gardens for a touch of old-world charm, combining it with roses, delphiniums, and other traditional cottage garden plants.

Planting and Care

Planting

• Timing: Plant Digitalis in the spring or fall when the ground is not frozen or waterlogged.
• Location: Choose a location with well-draining soil and good light conditions. Digitalis prefers full to partial sun, but in hot climates, it benefits from more shade.
• Soil: Digitalis thrives in moist, well-drained soil high in organic matter. It prefers slightly acidic soil.
• Depth and Spacing: Plant Digitalis so that the crown of the plant is at the soil level. Space the plants 18 to 24 inches apart to allow for proper growth and air circulation.
• Container Planting: When planting in containers, use good quality, well-draining soil, and a pot with adequate drainage holes.

Care

• Watering: Digitalis prefers consistently moist soil, especially during the first growing season. Water regularly, particularly during dry spells, but avoid overwatering, which can lead to root rot.
• Fertilizing: Digitalis generally does not require fertilization in organically rich soil. However, if your soil is poor, you can apply a balanced, slow-release granular fertilizer in the spring.
• Pruning: To encourage repeat blooming, remove the central flower stalks after the first flush of flowers. This will promote lateral branching and a second round of blooms. After the second bloom, leave the flower heads in place on biennial plants to allow them to reseed. Deadhead after flowering to avoid excessive seedlings but allow some flowers to go to seed to maintain a permanent planting.
• Staking: Taller varieties may need staking to prevent them from flopping over, especially in windy locations.
• Pests and Diseases: Monitor plants for potential pests like aphids and mealybugs, and diseases such as powdery mildew, verticillium wilt, and leaf spot.
• Winter Care: After the plants have gone to seed, cut back the foliage to just above the crown at ground level. Apply a layer of mulch to help retain moisture and protect the plants from frost heave. Overwinter first-year plants by covering them with a thick layer of mulch after the ground freezes.
• Transplanting: If you need to move your foxgloves, it is best done in the cooler weather of spring or fall to avoid heat stress.
• Propagation: You can propagate Digitalis by letting the plants self-seed or by sowing seeds yourself. Avoid heavy mulching, which can prevent reseeding.

A Note of Caution While Digitalis is a beautiful and beneficial plant, it is important to remember that all parts of the plant are toxic if ingested. Symptoms of Digitalis poisoning can include confusion, irregular pulse, nausea, vomiting, diarrhea, and vision changes. Keep Digitalis out of reach of children and pets, and wear gloves when handling the plant.

Seed Starting If you are starting Digitalis from seed, sow them indoors 8-10 weeks before the last frost. Use a seed-starting mix and barely cover the seeds, as they need light to germinate. Keep the soil moist and warm (around 20°C or 68°F). Germination typically takes 2-3 weeks. Once the seedlings are large enough to handle, transplant them into individual pots and gradually acclimate them to outdoor conditions before planting them in the garden.

Embrace the "Controlled Chaos" One interesting approach to growing Digitalis is to embrace a bit of "controlled chaos" in the garden. Allow some plants to go to seed and self-sow, creating a naturalized look with foxgloves popping up in unexpected places. This can add a sense of whimsy and surprise to your garden.

Digitalis, with its captivating beauty, fascinating history, and ecological importance, is a truly remarkable plant for any garden. Its medicinal uses, attractiveness to pollinators, adaptability to different environments, and genetic diversity make it a standout in the plant world. Whether you are drawn to the classic purple hues of Digitalis purpurea or the vibrant colors of its many cultivars, foxgloves are sure to add a touch of magic to your garden.

By understanding its unique features, growth habits, and care requirements, gardeners can successfully cultivate these stunning blooms and enjoy their dramatic presence in the landscape. Remember to plant and care for Digitalis responsibly, considering its toxicity and taking necessary precautions. Now that you are equipped with this knowledge, explore the world of Digitalis, and let its enchanting blooms grace your garden.