Penstemon digitalis, foxglove beardtongue
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Perennials

Penstemon digitalis

foxglove beardtongue

Scrophulariaceae

Eastern and central United States (Maine to South Dakota, south to Florida and Texas)

At a Glance

TypePerennial
HabitUpright
FoliageSemi-evergreen
Height24-48 inches (60-120 cm)
Width18-24 inches (45-60 cm)

Growing Zones

USDA Hardiness Zones

3 - 8
Zone 3
Zone 4
Zone 5
Zone 6
Zone 7
Zone 8
These zones indicate the coldest temperatures this plant can typically survive.
Frost Tolerancehardy

Key Features

Attracts Pollinators
Attracts Butterflies
Attracts Hummingbirds
Deer Resistant
Drought Tolerant
Native to North America
Maintenancevery low

Overview

An upright, clump-forming perennial in the family Plantaginaceae (formerly Scrophulariaceae), native to the eastern and central United States, growing in open woodlands, prairies, meadow edges, and roadsides. Plants form basal rosettes of smooth, lance-shaped to elliptic, semi-glossy leaves 2–5 inches (5–13 cm) long that often develop attractive reddish or burgundy tints, particularly in the cultivar 'Husker Red' (Perennial Plant of Year 1996). From late spring to early summer, stiff, erect stems 24–48 inches (60–120 cm) tall bear multi-branched panicles of tubular, two-lipped white flowers 1–1.25 inches (2.5–3 cm) long with faint purple guidelines inside the throat that guide pollinators to nectar. The inflated, foxglove-like flower tube gives the species its common name. Long-tongued bumblebees are the primary pollinators; hummingbirds also visit. Penstemon digitalis is among the most adaptable and cold-hardy penstemons, tolerating heavier and moister soils than most western species. Self-seeds freely when conditions suit. Non-toxic.

Native Range

Native to the eastern and central United States from Maine to South Dakota, south to Florida and Texas, growing in open woodlands, prairie edges, old fields, and roadsides in average to moist, well-drained soil in full sun to partial shade.

Suggested Uses

Planted in native perennial borders, prairie gardens, meadow plantings, and cottage gardens at 18–24 inch (45–60 cm) spacing. 'Husker Red' is valued for its reddish-burgundy foliage as much as its flowers — an outstanding foliage perennial from spring through fall. Effective in naturalistic combinations with ornamental grasses, coneflowers, and black-eyed Susans. Supports native long-tongued bees and hummingbirds.

How to Identify

Identified by smooth, semi-glossy lance-shaped leaves (often reddish-tinted, particularly in 'Husker Red'), stiff erect stems 24–48 inches (60–120 cm) tall, and panicles of tubular white two-lipped flowers 1–1.25 inches (2.5–3 cm) long with faint purple guidelines inside the throat, in late May–July. The smooth foliage, inflated white tubular flowers with purple-lined throat, and tolerance of moist, heavier soils distinguishes it from most western penstemons.

Appearance

Size & Dimensions

Height2' - 4'
Width/Spread1'6" - 2'

Colors

Flower Colors

white
purple

Foliage Colors

green
red
burgundy

Fall Foliage Colors

red
burgundy

Bloom Information

Bloom Period

~6 weeks
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SpringSummer
Blooms late May through July in zones 3–8, typically 4–6 weeks of peak flowering. In the Pacific Northwest, blooms reliably in June–July. Flowers are attractive to long-tongued bumblebees and hummingbirds. After flowering, attractive oval seed capsules persist and provide self-seeding; deadheading controls self-seeding if not desired. 'Husker Red' provides reddish foliage interest from spring through fall beyond the bloom period.

Detailed Descriptions

Flower Description

white with faint purple guidelines inside the throat; tubular, two-lipped

Foliage Description

medium green to reddish-burgundy (especially in 'Husker Red'); smooth, semi-glossy, lance-shaped

Growing Conditions

Sun Requirements

Full Sun
Partial Shade
Requires 3-6 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range5.5 - 7.0(Neutral)
357912
Soil Types
loamclaysand
Drainage
well drained

Water & Climate

Water Needs

Low

Frost Tolerance

hardy

Time to Maturity

1 year

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Plant in full sun to partial shade in average to moist, well-drained to average soil with a pH of 5.5–7.0. More tolerant of clay and moisture than most penstemons — one of the few that thrives in Pacific Northwest garden conditions without requiring rocky, dry soil. Drought-tolerant once established. Deadhead to prevent excessive self-seeding or allow seed to naturalize. Divide every 3–5 years in early spring to maintain vigor. Short-lived perennial (3–5 years) but self-seeds to maintain a garden presence.

Pruning

Cut back spent flower stems to the basal rosette after blooming to encourage fresh foliage and prevent self-seeding if not desired. Allow some seed capsules to mature for naturalized self-seeding colonies. Cut all stems to ground level in late fall or early spring. Divide every 3–5 years in early spring; alternatively, allow self-seeded plants to replace aging individuals.

Pruning Schedule

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Maintenance Level

very low

⚠️ Toxicity Warning

Non-toxic