Foxglove, known botanically as Digitalis, presents a striking vertical accent in garden landscapes with its distinctive bell-shaped blooms arranged along tall spires. These charming flowers are a popular choice for gardeners seeking to add height and visual interest. While discussions often include “blue” foxgloves, it is important to understand that truly blue varieties are uncommon in nature. What gardeners typically refer to as “blue” are specific cultivars that exhibit shades of purplish-blue, violet-blue, or even grey-blue, providing a cool-toned palette that complements many garden designs.
Understanding “Blue” Foxglove Varieties
The genus Digitalis encompasses a range of species, with Digitalis purpurea being the most recognized common foxglove. This species is available in various hues, including pink, purple, white, and yellow. Certain Digitalis purpurea cultivars display colors leaning towards lavender or purplish-blue, creating the desired “blue-like” effect. Examples include the ‘Camelot’ series with lavender blooms and ‘Excelsior’ with purple shades.
Other species, such as Digitalis parviflora, feature amber, brown, or chocolate-colored flowers, often with subtle violet veining. These do not fall into the blue spectrum. The “blue” perception in foxgloves refers to the deeper purplish or violet tones found within Digitalis purpurea selections.
Planting and Growing Blue Foxgloves
Foxgloves generally thrive in full sun to partial shade. In regions with intense summer heat, providing afternoon shade can prevent stress and maintain plant vigor. They prefer well-draining, fertile soil with a slightly acidic to neutral pH, ideally between 6.0 and 7.0. They can adapt to various soil types, including loamy or sandy compositions, as long as drainage is adequate.
When planting from seed, sow them directly onto the soil surface without covering, as light is necessary for germination. Seeds can be started indoors 8 to 10 weeks before the last frost or direct-sown in late summer to early fall. For transplants, dig a hole large enough to accommodate the root system, spacing plants 12 to 24 inches apart to allow for mature growth. Ensure the soil remains consistently moist, especially during the initial growing season, to help new plants establish robust root systems. Foxgloves are typically hardy in USDA zones 4 through 9, though some varieties extend this range to zone 3 or 10.
Ongoing Care for Blue Foxgloves
Once established, foxgloves need consistent moisture, especially during dry periods, though they tolerate some drought. Mulching around the base helps retain soil moisture, suppress weeds, and regulate soil temperature. Fertilization is often unnecessary in rich soil. If soil is poor, apply a balanced, slow-release granular fertilizer in spring as new growth emerges. High-phosphorus fertilizers support blooming.
Deadheading spent blooms encourages smaller, secondary flower spikes and prevents excessive self-seeding. To deadhead, cut the faded flower stalk a quarter-inch above the next set of leaves or down to the basal rosette, using clean, sharp pruning shears. Foxgloves are robust but can face issues like aphids, powdery mildew, or root rot. Good air circulation and well-draining soil prevent fungal diseases, while insecticidal soap manages aphid populations. For perennial varieties, leaving spent foliage over winter offers some crown protection; prune dead material in early spring.
Important Safety Considerations
All parts of the foxglove plant (leaves, flowers, seeds, roots) contain cardiac glycosides and are highly toxic if ingested by humans or pets. Symptoms of poisoning include nausea, vomiting, diarrhea, abdominal pain, and dizziness. More severe reactions involve irregular heartbeats, visual disturbances (blurred vision or halos), confusion, and lethargy. Ingestion can lead to serious cardiac issues and, in extreme cases, be fatal.
Exercise caution when handling foxgloves. Wear gloves to prevent skin irritation or absorption through cuts, and wash hands thoroughly afterward. To ensure safety, avoid planting foxgloves in areas accessible to young children or pets. Educate individuals about the dangers of ingesting any part of the plant, emphasizing it is for ornamental purposes only.
Designing with Blue Foxgloves
Blue-toned foxgloves offer a dramatic vertical element for garden spaces. Their tall spires add height and architectural interest to the back of borders or against fences and hedges. They fit well into cottage gardens, woodland settings, and mixed perennial beds, enhancing naturalistic or formal aesthetics.
These plants pair well with companions that complement their form and color. Plant them alongside mounded plants like hostas or ferns, which provide textural contrast with their broad foliage. For a harmonious display, combine them with other tall perennials such as delphiniums, lupines, or salvias, which also offer vertical appeal. Roses and peonies are classic companions, creating a romantic, layered look in cottage garden designs.