Blue foxglove adds vertical interest and color to garden spaces with its distinctive spires of bell-shaped blooms. Its striking appearance makes it a popular choice and a focal point in many garden designs.
Understanding Blue Foxglove
Blue foxglove refers to Digitalis varieties with bluish or purplish-blue flowers, as true blue is rare in the genus. Digitalis purpurea, common foxglove, primarily features purple, pink, white, and yellow, but specific cultivars have strong blue or lavender tones. Most are biennial, forming a leaf rosette in their first year and flowering in their second before dying. Some varieties are short-lived perennials, returning for a few years, or true perennials like Digitalis grandiflora, which can also have bluish tendencies.
Foxglove plants are tall, reaching 2 to 5 feet. Their spirally arranged leaves are 4 to 14 inches long and 2 to 5 inches wide, often covered with fine, glandular hairs. Tubular, bell-shaped flowers are densely arranged along an elongated cluster at the stem’s top. Each flower often features speckled interiors, guiding pollinators like bumblebees to nectar. These plants are native to Europe, western Asia, and northwestern Africa, thriving in woodland areas.
Growing Blue Foxglove
Successful cultivation of blue foxglove requires proper site selection and soil preparation. Foxgloves prefer partial shade, mimicking their natural woodland habitat. Some varieties tolerate full sun, especially in cooler climates, but afternoon shade is beneficial in warmer regions. They thrive in well-draining, fertile soil rich in organic matter, with a slightly acidic to neutral pH (6.0-7.0). Incorporate a 3 to 4-inch layer of compost or well-rotted manure before planting to improve soil.
Space plants 1 to 2 feet apart for air circulation, which prevents fungal diseases. Seeds can be sown directly outdoors in late spring or early summer, or indoors 10 to 12 weeks before the last frost. Foxglove seeds need light to germinate, so press them onto the soil surface without covering. Germination occurs within 2 to 3 weeks at 65°F to 75°F. Transplant seedlings into the garden in early fall to establish roots before cold weather.
Water consistently, especially during establishment and dry periods. Foxgloves prefer moist, not waterlogged, soil to prevent crown rot. Provide about 1 inch of water per week. Mulch around the base with a 2 to 3-inch layer of organic material to retain moisture, suppress weeds, and regulate soil temperature. While not heavy feeders in good soil, a light application of a slow-release, balanced granular fertilizer in early spring supports vigorous growth and blooming. An NPK ratio around 1-4-2, with higher phosphorus, benefits flowering and root development. Avoid high nitrogen fertilizers, which inhibit flower production.
Maintenance extends the plant’s display and manages its spread. Deadheading spent flower spikes encourages a second, smaller flush of blooms and prevents excessive self-seeding. If natural reseeding is desired, leave some flower spikes to mature. Taller varieties may require staking. Foxgloves are resistant to deer and rabbits due to their toxicity. Propagation occurs through self-seeding or by collecting seeds.
Toxicity and Safe Handling
All parts of the foxglove plant are toxic if ingested by humans or pets, including flowers, seeds, leaves, and stems. The plant contains potent cardiac glycosides, such as digoxin, which affect heart function. Symptoms of poisoning include nausea, vomiting, dizziness, abdominal pain, irregular heart rhythm, and tremors. In severe cases, ingestion can lead to serious cardiac issues or be fatal.
Exercise caution when handling foxglove. Wear impermeable gloves to prevent skin absorption, especially when pruning or collecting seeds, and wash hands thoroughly afterward. Avoid burning any plant parts, as the smoke is poisonous. Plant foxgloves in areas not easily accessible to young children or pets, and ensure no part of the plant is chewed or ingested. The toxins are not diminished by drying or boiling, so avoid using foxglove in teas or any form of consumption.