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Large Flowered Beardtongue, Shell-leaf Penstemon

Penstemon grandiflorus

Family: Plantaginaceae
Genus: Penstemon (PEN-stem-on) (Info)
Species: grandiflorus (gran-dih-FLOR-us) (Info)



Foliage Color:

Unknown - Tell us

Bloom Characteristics:

This plant is attractive to bees, butterflies and/or birds

Water Requirements:

Average Water Needs; Water regularly; do not overwater

Where to Grow:

Unknown - Tell us


36-48 in. (90-120 cm)


18-24 in. (45-60 cm)


USDA Zone 3a: to -39.9 C (-40 F)

USDA Zone 3b: to -37.2 C (-35 F)

USDA Zone 4a: to -34.4 C (-30 F)

USDA Zone 4b: to -31.6 C (-25 F)

USDA Zone 5a: to -28.8 C (-20 F)

USDA Zone 5b: to -26.1 C (-15 F)

USDA Zone 6a: to -23.3 C (-10 F)

USDA Zone 6b: to -20.5 C (-5 F)

USDA Zone 7a: to -17.7 C (0 F)

USDA Zone 7b: to -14.9 C (5 F)

USDA Zone 8a: to -12.2 C (10 F)

USDA Zone 8b: to -9.4 C (15 F)

USDA Zone 9a: to -6.6 C (20 F)

USDA Zone 9b: to -3.8 C (25 F)

Sun Exposure:

Full Sun


Unknown - Tell us

Bloom Color:


Bloom Time:

Late Spring/Early Summer



Other details:

This plant may be considered a protected species; check before digging or gathering seeds

Soil pH requirements:

Unknown - Tell us

Patent Information:


Propagation Methods:

Unknown - Tell us

Seed Collecting:

Unknown - Tell us


This plant has been said to grow in the following regions:

Wasilla, Alaska

Stockton, California

Aurora, Colorado

Colorado Springs, Colorado

Iowa City, Iowa

Pacific Junction, Iowa

Yale, Iowa

Luverne, Minnesota

Minneapolis, Minnesota

Saint Paul, Minnesota

Denville, New Jersey

Riverton, Utah

Leesburg, Virginia

show all

Gardeners' Notes:


On Jun 11, 2015, Chillybean from Near Central, IA (Zone 5a) wrote:

This prairie beauty resides in my native patch near the driveway. Mine were grown from seed collected in Iowa from pure untouched prairies. This plant likes sandy/rocky soil. All that gravel I usually battle with is bound to be of some use. It can tolerate dry conditions and this spot fits the bill except during the heavy rains we occasionally get. They were put into the ground July 2014 as plugs before they went into dormancy for the year. Now came the long wait... will they survive?

To my surprise they came back and developed nicely, but only one got so far as to grow the single tall stem that flowered. I read these plants do not like competition and they share space with an exuberant Bee Balm (Monarda fistulosa). I may try to move them, but let the one go to seed fi... read more