Falling in Love with Foxglove

FOXGLOVE BASICS

Botanical name:

Digitalis (from the Latin word digitus, or finger).

Type:

Biennial or perennial, depending on the species.

Zones:

4-8 for most biennial varieties, some perennials are hardy to zone 3.

Height:

1 to 2 feet for dwarf varieties; 3 to 6 feet for others

Flower characteristics:

Both the common and botanical names of foxglove refer to the resemblance of the flowers to the fingers of a snipped-off glove. They grow along the length and sometimes fully encircle tall spikes that taper toward the top like cathedral spires, rising dramatically above low-growing rosettes of dark green foliage. The color palette is primarily soft pastels, often accentuated by darker speckled or veined markings.

Bloom time:

Late spring to midsummer.

Pros:

• Attracts bees and hummingbirds
• Low maintenance
• Deer and rabbit resistant
• Shade tolerant

Cons:

• You might recognize "digitalis" as the name of a heart medicine, which is derived from foxglove and is beneficial in controlled doses. However, all parts of the plant itself are highly toxic if ingested. (See more Common Poisonous Plants for Dogs and Cats.)
• Most biennial foxgloves will not bloom the first year they are planted, but there are some exceptions, such as Digitalis purpurea 'Foxy' and D. purpurea 'Camelot Rose.'
• The flowers are not fragrant.

Common species:

• Digitalis purpurea (common foxglove): The most widely grown species, available in a multitude of cultivars in a broad spectrum of colors, often with attractive spotted throats. Typically a biennial or short-lived perennial. Invasive in some zones/ecosystems (see map). Height: 3 to 4 feet.
• Digitalis grandiflora (yellow foxglove): A beautiful perennial foxglove, with soft lemon-yellow blooms accented by lacy brown veining on the inside. “One the toughest and best-performing members of its clan,” says Hodgson. Height: 2 to 3 feet.
• Digitalis xmertonensis (strawberry foxglove): A hybrid of D. purpurea and D. grandiflora that bears strawberry-pink blooms. Although it’s often considered a short-lived perennial, you can often extend its lifespan by cutting the flower stalks back before they go to seed. Height: 3 to 4 feet.
• Digitalis ferruginea (rusty foxglove): One of the tallest foxgloves, producing spikes of densely packed golden-yellow flowers with brownish-red veining. Height: 4 to 6 feet. (See 12 Flowering Plants for the Summer Garden).

GROW YOUR OWN

Light requirements:

Plant foxglove in a shady to partly sunny location in moist, well-drained soil. The hotter the climate, the more shade your plants will need. Avoid direct afternoon sunlight, which can scorch the leaves.

Soil:

Foxglove thrives in soil that’s high in organic matter and slightly acidic. In alkaline soils, use an organic base soil acidifier to lower the soil pH. See these tips for testing the pH of your soil.

How to plant:

It couldn’t be easier to start foxglove plants from seeds. Because they need light to germinate, simply scatter the seeds on top of the soil and lightly rake them into the surface, leaving them exposed. Keep the soil moist, and once your seedlings emerge thin them to a spacing of 18 to 24 inches to prevent overcrowding.

When to plant:

You can start foxglove seeds indoors in late winter or sow them directly in the garden in spring after the danger of frost has passed. In warmer zones, they can also be started in the fall. The seedlings will emerge in about 2 to 3 weeks, depending on weather conditions. Remember that biennial varieties will not bloom or produce seeds the first year, so you must plant them two years in succession to enjoy new blooms each summer.

Propagating:

Let plants self-seed or sow the seed yourself. Avoid heavy mulching, which will prevent reseeding. To prevent overcrowding, divide clumps of perennial foxglove (not the biennial ones) every few years by separating new plantlets from the crown and replanting at the same depth. If you have a foxglove sprouting up where you don’t want it, simply dig up the root ball and transplant it to another part of the garden. Transplanting and dividing is best done in the cooler weather of spring or fall so your plants won’t suffer from heat stress.

Using in the garden:

Foxglove’s showy spikes of flowers are perfect for creating vertical focal points in cottage gardens, woodland gardens, and other informal plantings.

• In a cottage-style garden, mix foxglove with other shade-tolerant plants of various shapes, colors, and sizes, such as oriental poppy (Papaver orientale), bellflowers, garden phlox (Phlox paniculata), hardy geraniums, bleeding hearts, and astilbes.
• In a woodland garden, combine foxglove with hostas, ferns, and woodland phlox (Phlox divaricata).
• Foxgloves are especially dramatic when massed in groups of five or more plants, especially if you choose a variety that comes in a mixture of colors, such as D. purpurea ‘Foxy’.

CARE TIPS

Watering:

Foxglove is not very drought tolerant, so regular watering is a must during prolonged dry spells, especially for new plants that aren’t yet established. Once your plants become well-rooted, they can tolerate some dryness as long as they aren’t exposed to full sunlight.

Staking:

The flower stalks of foxglove are thick and sturdy and usually require no staking. However taller varieties that grow to heights of 5 feet or more may need some support to prevent them from bending and breaking in the wind and to keep the flower stalks upright.

Pruning:

Many foxgloves will reward you with an encore performance if you remove the central flower stalks after they bloom, which will encourage lateral branching and a second round of blooming. After the second bloom, leave the flower heads in place on biennial plants so they will reseed and continue the two-year cycle. If your plants start to look a bit scruffy toward the end of the growing season, you can improve their appearance while ensuring some reseeding by cutting down most but not all of the flower spikes.

Winter care:

Once your plants have gone to seed, you can remove all the spent flowers and cut back the foliage to just above the crown at ground level. Remove second-year biennial plants that have finished blooming to make room for new plants to grow from seed in the spring. To help retain moisture and protect your plants from frost heave, cover them with a 4- to 5-inch layer of mulch. (See How to Mulch.)

Pest and disease control:

Foxglove is highly resistant to most pests, with the exception of slugs, which love to munch on the leaves. You can pick them off by hand or deter them by sprinkling a commercial slug bait around the plant or creating a simple do-it-yourself trap using a shallow bowl filled with beer. Most of the common diseases that plague foxglove — including leaf spot, powdery mildew and crown rot — are easy to avoid by giving your plant adequate drainage and good air circulation. Also use soaker irrigation rather than overhead watering. Promptly remove any dead or diseased leaves.

FOXGLOVES WE LOVE

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Photo by: Ole Schoener / Shutterstock.

Digitalis purpurea 'Foxy'

This versatile foxglove is one of the few that blooms reliably from seed its first year, giving you the flexibility to grow it as an annual or a biennial. If grown as an annual, start seeds indoors in late winter and transplant them outside in the spring. Blooms typically appear about 5 months after seeding. Flower colors include creamy white, yellow, rose and pink with maroon-spotted throats.

Zones: 4-8

Height: 2 to 3 feet

Photo by: Ole Schoener / Shutterstock.

Digitalis purpurea 'Candy Mountain'

'Candy Mountain' lets you view foxglove from a new perspective, turning the usual downward-facing flowers upward so you can easily gaze at the beautifully speckled throats of these rosy pink blossoms. Even better, the blooms surround the entire stalk so you can appreciate them from every angle. The densely packed flower spikes stand upright in the garden without staking and are a striking addition to cut-flower arrangements.

Zones: 4-8

Height: 3 to 4 feet

Photo by: Tim Ludwig / Millette Photomedia.

Digitalis grandiflora ‘Carillon’

If you’re looking for a foxglove that you can grow in containers or at the front of the garden in shady borders, you can’t go wrong with this dwarf grandiflora. The smallest of all the foxglove varieties, it grows to just over a foot tall and bears an abundance of lovely soft-yellow flowers from June through August. Like larger yellow foxgloves, it is reliably perennial.

Zones: 3-8

Height: 12 to 15 inches

Photo by: Christine Petersen / Millette Photomedia.

Digitalis ferruginea 'Gelber Herold'

Sometimes sold as 'Yellow Herald' (gelb in German means yellow), this unusual biennial variety is distinguished by its sepia color tones and dark veining. “This rare foxglove is one of my favorites,” says Diane Linsley of Diane’s Flower Seeds, an online retailer of heirloom seeds. “It blooms in midsummer with towering spikes of soft tan-yellow flowers with rusty veining. The flowers are larger than the species, and it self-sows freely in my zone 5 garden.” A close and equally attractive relative is D. ferruginea ‘Gigantea’, which produces towering spikes of honey-brown flowers.

Zones: 4-8

Height: 3 to 6 feet

Photo by: Garden World Images Ltd / Alamy Stock Photo.

Digitalis 'Polkadot Pippa’

One of the members of the Polkadot series of foxglove hybrids, Pippa has an exceptionally long bloom time, beginning in late spring and continuing into autumn. The luscious deep rose and apricot flowers with yellow-spotted throats are spaced evenly around the entire stalk, rising above large rosettes of downy green leaves. Like all the Polkadot hybrids, Pippa is reliably perennial with sterile flowers that don’t self-seed. Also try ‘Polkadot Petra’ (soft pink flowers and creamy white throats speckled in brown) and ‘Polkadot Polly’ (pink and apricot flowers, subtly speckled in white).

Zones: 4-9

Height: 2 to 3 1/2 feet

Photo by: Ole Schoener / Shutterstock.

Digitalis purpurea 'Camelot Rose'

Unlike most biennial foxgloves, ‘Camelot Rose’ flowers reliably its first year and even more heavily the second year before finally setting seed. The rose-colored blooms open in late spring to reveal showy pink throats accented with dark purple speckles, with the flowers often lasting through midsummer. Also try ‘Camelot Cream,’ which has soft creamy-white blooms with maroon markings.

Zones: 4-8

Height: 3 to 4 feet

Photo by: Steffen Hauser / botanikfoto / Alamy Stock Photo.

Digitalis obscura (Sunset foxglove)

This sun-loving shrublike perennial foxglove, native to the mountains of Spain, has little in common with others in the species, to the delight of gardeners who have no shade. Not only does it tolerate full sun and hot, dry conditions, it will also thrive in moister, shadier sites. The alluring trumpet-shaped flowers blend all the warm color tones of the setting sun, including primrose yellow, peach, red and gold. The glossy willow-like foliage is also highly ornamental and remains evergreen in mild climates.

Zones: 4-9

Height: 1 to 2 feet

Photo by: Rock Giguère / Millette Photomedia.

Digiplexis Illumination® Flame

This recently introduced hybrid, bred by Thompson and Morgan, is the beautiful love child of common foxglove (D. purpurea) and its tropical counterpart Canary Island foxglove (Isoplexis canariensis). It produces gorgeous spikes of fuchsia blooms with throats that transition from red to orange to pale yellow, like a floral flame. What’s more, the blooms continue nonstop from late spring until the first frost, so you can enjoy them the entire season. Unlike most foxgloves, it also has a bushy growth habit with numerous flower-laden lateral shoots. A tender perennial that can be grown as an annual in cooler climates. Also try these other Digiplexis varieties: Illumination ‘Raspberry’ (raspberry pink flowers with orange throats) and ‘Berry Canary’ (hot-pink flowers with creamy yellow burgundy-speckled throats).

Zones: 8-10

Height: 3 feet

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