The Story
Plant Bio
Penstemon grandiflorus is an upright herbaceous perennial native to central North American prairies, forming unbranched stems two to four feet tall from a basal rosette. Its thick, smooth leaves are silver-blue and glaucous, clasping the stems beneath open spikes of large tubular flowers in late spring.
The species produces some of the largest flowers in the genus, measuring up to two inches long in shades of lavender, pinkish-blue, or light purple. Its glaucous, waxy leaf coating reflects intense heat and conserves moisture in open, sun-baked environments.
Uses & Benefits:
Essentials
At a Glance
Plant Type
Perennial
Height
48"
Width
24"
Light
Full Sun
Zones
4, 5, 6, 7, 8, 9
Water
Low
Humidity
Low to Moderate
Lifespan
Short-lived Perennial
Native To
Central North America
Toxicity
Non-toxic
Bloom period
Late spring – Early summer
In flower about 2 months of the year
Marketplace
Where to Buy
Shipping costs Year-round shipping Free shipping
Planting
How to Grow
- Select a site in full sun with gritty, sandy, or gravelly soil that does not retain standing water.
- Plant dormant crowns or potted stock with the soil line matching the crown height.
- Water lightly at planting to settle soil around roots, then cease supplemental watering once established.
- Cut spent flower stalks back to the basal rosette after bloom finishes to preserve plant strength.
Pro Tip
Plant in lean, gravelly, or sandy soil with fast drainage; excess moisture or rich organic matter triggers fatal crown and root rot.
Keep It Thriving
Care Guide
Do
- Plant in sharply draining, sandy or gravelly soil.
- Provide full sun exposure to maintain sturdy, upright stems.
- Cut spent flower stalks back to basal foliage to prolong plant vigor.
Don't
- Do not add rich compost or high-nitrogen fertilizers.
- Do not overwater or plant in heavy clay soils.
- Do not cut back into old woody base tissue.
Seasonal Care Calendar
| Task | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Pest Check | ||||||||||||
| Prune | ||||||||||||
| Spring Cleanup | ||||||||||||
| Winter Prep |
Watch Out For
Pests & Diseases
Common Pests
Common Diseases
In the Garden
Landscape Uses & Companions
Landscape Uses
Multiply
Propagation Methods
Good to Know
Common Questions
Large Beardtongue questions
What zones can Large Beardtongue grow in?
Large Beardtongue is hardy in USDA Zones 4–9. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.
Is Large Beardtongue deer resistant?
Not reliably. Deer may browse Large Beardtongue, especially tender spring growth — plan on repellents or fencing where pressure is high.
When does Large Beardtongue bloom?
Large Beardtongue typically blooms in late spring through early summer. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.
Does Large Beardtongue need full sun?
Large Beardtongue does best in full sun (6+ hours).
Is Large Beardtongue drought tolerant?
Yes — once established (usually after the first full season), Large Beardtongue handles dry spells with minimal watering. Water deeply its first year to build the root system that makes that possible.
More Penstemon to compare
Beardtongue Rondo
Penstemon barbatus 'Rondo'
George Home Penstemon
Penstemon digitalis 'George Home'
Foxglove Beardtongue
Penstemon digitalis
Blue Springs Penstemon
Penstemon heterophyllus 'Blue Springs'
Blackbeard Beardtongue
Penstemon digitalis 'Blackbeard'
Dark Towers Penstemon
Penstemon digitalis 'Dark Towers'
Keep exploring
Explore the genus
Grow Large Beardtongue with confidence
See it in a design of your actual yard, get zone-matched care reminders, and track it season by season in your garden journal.