Foxglove beardtongue
Penstemon digitalis
A native upright perennial of central + eastern North American prairies, woodland margins, and open woods producing tall vertical spires of white tubular flowers in late spring. The species name "digitalis" honors a flower-shape resemblance to true foxglove (Digitalis purpurea) — but Penstemon digitalis is NOT toxic in the same way (NC State explicit: "lacks the toxicity associated with foxglove"). Specialist Penstemon mason bee (Osmia distincta) relationship per NC State. The popular 'Husker Red' cultivar adds burgundy foliage for foliage-color design.
Native: 35 US states + 4 CA provinces
Climate fit: broad (87/100)
Pollinator
Border
Focal point
Light
Full sun / Part shade
Water
Moderate water
Mature size
24-48" tall · 18" apart
Hardy in zones
3a-8b
brutally cold to frosty winters
AHS heat range
1-11
Plant range authored in AHS heat-zone terms.
Native in Illinois
Yes
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A documented larval host for the Common buckeye — caterpillars feed on its foliage before becoming the next generation.
Cold hardiness
These values are location-based: this location's current hardiness is the baseline, and the 2050 value is a projected future climate for this same location.
Now
Zone 6b
Plotwright
USDA Zone 6b
-5°F to 0°F
Well-suited
Zone 7a
Plotwright
0°F to 5°F
Well-suited
In plain terms: This location has cold winters. Its winters are projected to keep warming through 2050.
✓
Well-suited today and still thriving in 2050.
Heat tolerance
Heat tolerance values are location-based too: heat days today are observed at this site, and the 2050 value projects this same location under a future climate.
Loading AHS heat-zone data for this location...
Where this plant fits
Suitable across 40 ecoregions — 35 climate-resilient through 2070 · 5 suited today. Best matches first.
Appalachian mixed mesophytic forests
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Appalachian-Blue Ridge forests
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Arizona Mountains forests
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Blue Mountains forests
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Canadian Aspen forests and parklands
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Central Pacific Northwest coastal forests
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Central Tallgrass prairie
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Central-Southern Cascades Forests
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Colorado Rockies forests
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Cross-Timbers savanna-woodland
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Similar plants
Browse lateral options with similar roles, light needs, size, or native-range overlap; these are not filtered for a better climate fit.
Baptisia australis
Blue false indigo
A long-lived native perennial of central and eastern US woodland borders and prairie meadows with deep blue pea-shaped flowers in late spring, blue-green leguminous foliage, attractive black seed pods for winter interest, and a nitrogen-fixing root system (Fabaceae). Larval host for 6 documented butterfly species per NC State (orange sulphur, clouded sulphur, frosted elfin, eastern tailed-blue, hoary edge, wild indigo duskywing) — among the highest Lep-host-count perennials in the eastern flora.
Lobelia cardinalis
Cardinal flower
A short-lived native perennial of wet woodland edges, stream banks, and ditches across the Americas, named for the brilliant scarlet-red flowers that rise on erect, unbranched terminal spikes from mid-to-late summer. Each tubular, two-lipped bloom is shaped for the hummingbird tongue — the plant depends on ruby-throated hummingbirds for pollination because most insects cannot work the long flower tube. It demands constant moisture and tolerates brief flooding, but its foliage carries alkaloids that are very toxic to humans if eaten.
Hibiscus moscheutos
Hardy hibiscus
A bold, moisture-loving native perennial of eastern North America that dies back to a woody base each winter and returns to throw up stout 2-6 ft stems topped with enormous 4-8 inch saucer-shaped flowers — white, pink, red, or burgundy, each with a contrasting central eye — from June into September. NC State Extension describes a herbaceous perennial hardy across USDA zones 4a-9b that thrives in wet to constantly moist soils, tolerates heat, humidity, and even brief flooding, and draws hummingbirds, butterflies, and other pollinators. The tropical-looking dinner-plate blooms make it a dramatic focal point for rain gardens, pond edges, and the back of a sunny border.
Asclepias incarnata
Swamp milkweed
A more refined garden-behaved cousin of common milkweed (Asclepias syriaca) — same monarch host status and ecological value, but clumping rather than aggressively spreading, well-suited to rain gardens and consistently moist sites. Pink fragrant flower clusters from mid-summer through early fall; 2005 NC Wildflower of the Year. NC State tags Poisonous (cardiac glycosides) — the same toxicity that makes monarch caterpillars unpalatable to vertebrate predators.
Spigelia marilandica
Indian pink
A native southeastern US perennial with red-and-yellow tubular flowers in upright clusters — among the most spectacular hummingbird-pollinated native perennials and a top-tier butterfly + pollinator garden plant. Shade-tolerant + clumping; slowly naturalizes by self-seeding in suitable conditions.
Hydrangea quercifolia
Oakleaf hydrangea
A four-season native shrub of the southeastern United States, where NC State Extension notes it grows wild in moist woods and along stream banks. It is an upright, multi-stemmed deciduous shrub, slow-growing to roughly 4-8 feet tall and 4-10 feet wide, named for its large, oak-shaped, lobed dark-green leaves. Showy pyramidal 4-12 inch panicles of creamy-white flowers open from late spring into summer and fade to pink and then tan, while the bold foliage turns wine, orange, and mahogany in fall over peeling cinnamon bark. Easy and low-maintenance in organically rich, well-drained soil, it is grown as a specimen, in masses, or as an informal hedge.
Sources & citations
Cite this page
For lesson plans, articles, or research that uses this page. To cite a single upstream fact instead, use its specific source listed below.
Plotwright. (2026, May 17). Foxglove beardtongue (Penstemon digitalis). Retrieved 2026, June 24, from https://plotwright.com/plants/penstemon-digitalis
Sources for every fact
Every fact on this page traces to a source. 18 fields cited - 18 source-backed.
NC State Extension Gardener Plant Toolbox
University extension service
Backs 17 fields
Identity
Summary
Plant type
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Moisture
Hardiness
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Spacing
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