HARDINESS: Zones 4 to 9
PREFERRED SOIL pH: Near neutral
PREFERRED SOIL TYPE: Average, well-drained
PREFERRED LIGHT: Partial shade
ATTRIBUTES: Bell-shaped flowers in various colors on tall spikes; for beds
SEASON OF INTEREST: Late spring through summer
FAVORITES: Biennial 'Foxy', Excelsior hybrids; perennial D. grandiflora, 'Carillon'
QUIRKS: All parts of foxglove plants are toxic if eaten
GOOD NEIGHBORS: Columbine, ferns, hydrangea, roses, deciduous trees
WHERE IT GROWS BEST: Partial shade in moist, fertile, organic soil
POTENTIAL PROBLEMS: Root rot due to cold, wet winter weather
RENEWING PLANTS: Biennials live 2-3 years, start seeds; perennials live 2-4 years, divide
CRITTER RESISTANCE: Excellent, except slugs and snails
SOURCE: Seeds, division
DIMENSIONS: 2-5 ft (0.6-1.5 m) tall, 1 ft (0.3 m) wide; dwarf, 1 ft (0.3 m) tall, wide
Foxglove in the Landscape
Foxgloves dramatize the shade with masses of bell-shaped flowers aligned on 3-5 ft (1-1.5 m) spires.These flowers open gradually from bottom to top, which makes for a long show, and plants can sometimes be coaxed to bloom again if spent spikes are cut back. These are perfect plants for the edge of a woodland or a shaded entryway. Note that all parts of foxglove, which is the source of digitalis, a prescription heart medication, are toxic if eaten. Avoid siting them where children or pets may be tempted.
The common garden foxglove, Digitalis purpurea, is technically considered a biennial: It grows from seed one year, then blooms, sets seeds, and dies the next. Many foxgloves, however, prosper for up to 4 years, often self-sowing. The downy oval leaves form a rosette on young plants that spreads until, in the second spring, a flower spike appears. Varieties abound in a range of colors and sizes. 'Alba' has pure white blossoms with dark speckles at the throats. Excelsior hybrids offer a range of colors including pink and yellow. Fast-growing, 24 in (61 cm) tall 'Foxy' sometimes blooms the first year it's planted from seed.
A longer-lived perennial foxglove, D. grandiflora, has glossy foliage and buttery flowers with reddish speckles in the throat. It is hardy to Zone 5 and grows to about 2 ft (60 cm) tall. A new dwarf, named 'Carillon', is only 12 in (30.5 cm) tall and wide.
To be successful, you need only set out purchased plants, protect them from extreme cold with mulch, and wait for them to bloom the next year. To keep common foxglove coming back, learn to recognize the seedlings and move them while they're small.
Self-sown seedlings have the best chance of settling into the garden. In midsummer, you can also collect and
start seeds in a shady bed or in pots filled with sterile commercial seed-starting mix. Fresh seeds gathered from plants sprout in 10 days, but dried seeds from commercial seed packets can take several weeks. Barely press the seeds into the moistened mix, since they need light to germinate. After seedlings have 4-6 leaves, transplant them to the garden. Mulch lightly to protect them in winter.
Perennials should be divided every 3-4 years. Divide them in spring in cold climates and in late summer in warm areas, being sure to keep the soil moist until plants are established.
Though rarely bothered by insects, slugs and snails may visit. If you see ragged holes in leaves and flowers, set out shallow saucers of beer to attract and drown them, or handpick and dispose of the pests at twilight.