Penstemon, Beard Tongue, Beardtongue, Pride of the Mountain 'Dark Towers'

Penstemon digitalis

Family: Plantaginaceae
Genus: Penstemon (PEN-stem-on) (Info)
Species: digitalis (dig-ee-TAH-liss) (Info)
Cultivar: Dark Towers
Additional cultivar information:(PP20013)
Hybridized by Lindgren
Registered or introduced: 2007
View this plant in a garden



Foliage Color:


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:

Grow outdoors year-round

Suitable for growing in containers


18-24 in. (45-60 cm)

24-36 in. (60-90 cm)


15-18 in. (38-45 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)

Sun Exposure:

Full Sun

Sun to Partial Shade



Bloom Color:


Bloom Time:

Late Spring/Early Summer

Mid Summer


Grown for foliage



Provides winter interest

This plant is fire-retardant


Good Fall Color

Other details:

Unknown - Tell us

Soil pH requirements:

6.1 to 6.5 (mildly acidic)

6.6 to 7.5 (neutral)

7.6 to 7.8 (mildly alkaline)

Patent Information:


Propagation Methods:

By dividing the rootball

From softwood cuttings

Seed Collecting:

N/A: plant does not set seed, flowers are sterile, or plants will not come true from seed


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

Clovis, California

Cornwall Bridge, Connecticut

Cherry Valley, Illinois

Washington, Illinois

Rising Sun, Maryland

Norton, Massachusetts

Hopkins, Minnesota

Kasota, Minnesota

Saint Paul, Minnesota

Randolph, New Jersey

Apex, North Carolina

Elizabeth City, North Carolina

Zirconia, North Carolina

Amherst, Ohio

Lansdowne, Pennsylvania

Rockvale, Tennessee

Garland, Texas

Kalama, Washington

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Gardeners' Notes:


On Jan 31, 2016, coriaceous from ROSLINDALE, MA wrote:

'Dark Towers' is a seed strain developed by Dr. Dale Lindgren, a mathematician turned horticulturist, from the University of Nebraska. It represents a further development of 'Husker Red', which he also bred. 'Dark Towers' has deeper, more consistent burgundy foliage and pink-tinged flowers. It is also slightly taller.

Penstemon digitalis is one of the few penstemons that's long-lived in eastern N. America, where it's native. It needs only ordinary garden conditions and not rock-garden soil. Self-sows here more than I'd like, but it's a decent garden plant that makes a decent evergreen groundcover. The flowers are nice but the season of bloom lasts only about two weeks here in Boston MA Z6a. The seed capsules and stems are ornamental into the winter. The foliage has excellent... read more


On Jul 9, 2012, ms_greenjeans from Hopkins, MN (Zone 4a) wrote:

This is a lovely variety of penstemon. The foliage is very dark and glossy. It has a strong upright habit and long bloom period. The flowers are white, or nearly white, with a lavender blush. Quite pretty.


On Jun 4, 2012, myncgarden from Zirconia, NC wrote:

Second year, and only two plants, but they are both large and beautiful and look quite striking in the perennial border. Great dark burgundy foliage, stands out beautifully against a green backdrop; pale pink/white tinged flower. Plants are growing strong so far, getting about 5-6 hours of sun; no staking has been required. Each plant is about 3 ft tall and about half as wide and each one holds its own in a border where other perennials (agastache, coneflower, coreopsis, etc) are in large groupings. So far I highly recommend it.


On Jul 20, 2010, northgrass from West Chazy, NY (Zone 4b) wrote:

This plant is about 30 inches high, gets sun most of the day. It is its second year in my garden and looking good all season.