GardenersHQ

How to Grow Penstemon Plants

Guide to Growing Beard Tongue, Cows Tobacco and Balloon Flower

Penstemon plants are natives of Northern America. They can reach from 30 to 90 cm (1 to 3 feet) in height.

They can be grown in the garden as hardy perennials, half hardy annuals, or perennials.

Beard tongue

Penstemon bloom in the summer with tubular lipped flowers; these may be blue, pink, purple, white or yellow. A common name for Penstemon is Beard Tongue.

Penstemon
Penstemon by Creosoteshadow; creative commons.

Penstemon albidus
Penstemon albidus by Matt Lavin.

Commonly Grown Penstemon Species Photographs and Plant Identification

Penstemon eatonii

Penstemon eatonii
Penstemon eatonii (Eaton's Penstemon / firecracker Penstemon), photograph by Andrey Zharkikh; CC.

Penstemon strictus

Penstemon strictus
Penstemon strictus (Rocky Mountain Penstemon), photograph by Andrey Zharkikh; CC.

Penstemon hirsutus

Penstemon hirsutus
Penstemon hirsutus (Hairy Beard-tongue / Northeastern Beardtongue), photograph by Doug McGrady; CC.

Penstemon heterophyllus

Penstemon heterophyllus
Penstemon heterophyllus (Bunchleaf Penstemon / Foothill Beardtongue), photograph by Tom Hilton; CC.

Penstemon spectabilis

Penstemon spectabilis
Penstemon spectabilis (Showy Penstemon / Showy Beardtongue), picture by peganum; CC.

Penstemon Plant Growing and Care Guide

Common Names: Beard Tongue, Balloon Flower, Cows Tobacco. Penstemon: Garden; Phlox; Heller's; Firecracker; Border; Sand; Box; Parachute; White-margined; Bush; Foothill.
Family: Plantaginaceae.
Life Cycle: Hardy annual. Half hardy perennial, hardy perennial.
Height: 4 to 120 inches (10 to 300 cm).
Native: North America. East Asia.
Growing Region: Annual: zones 1 to 10. Perennial: zones 3 to 10.

Flowers: Summer.
Flower Details: Red, white, purple, lilac, yellow, blue, pink. Tubular. Two lips. Distinctive staminode.
Foliage: Herbaceous or shrub. Erect. Lanceolate to oblong.

Sow Outside: Surface. Spring and/or autumn. Spacing 12 to 48 inches (30 to 120 cm).
Sow Inside: Germination time: two to five weeks in the light. Temperature 60°F (16°C). Two months before expected last frost. Transplant outdoors following the last.

Requirements: Full sunlight or light shade. Good drainage. Soil pH 5.5 to 7. Rich soil. Regular watering during prolonged dry periods. Deadhead. Perennials should be cut back to the ground in autumn. Autumn mulch for perennials once cut back. Winter mulch. Propagate: cuttings can be took from stems in either autumn or in the spring.

How to Grow Beard Tongue and other Penstemon in the Garden

The seeds of Beard Tongue/Penstemon can be sown outdoors in either spring or autumn.

Penstemon plant seeds should be sown on the soil surface.

They like to grow in sunny areas (requires partially shade in hot areas).

Ideally the soil should be fertile and slightly acidic to neutral (pH 5.5 to 7).

The ground that the plant grows in should also have good drainage.

If starting off indoors, then do so about 9 or 10 weeks before the last expected frost of spring.

The seeds should be germinated in the light, at 12 to 18 degrees centigrade (54 to 64°F). Germination should take about 3 to 6 weeks.

Once ready, transfer the young Penstemon plants outside at a spacing of about 30 cm (12 inches; small species) to 75 cm (30 inches; larger varieties).

Caring for Beard tongue and other Penstemon plants in the garden.

To look after Beard tongue and other Penstemon plants, it is best to water regularly and to deadhead the flowers once they have finished blooming.

Once the season has finished in the autumn, cut the plants down to the ground.

It is a good idea to mulch the ground that Penstemon grow in at the same time.

If you require more plants for your garden, they can be propagated by taking stem cuttings. This can be done in either spring or autumn.

I hope that you enjoyed this guide on how to grow Penstemon plants. You may also enjoy the following Gardener's HQ growing guides: How to grow Purple Bell Vine, Iris plant, Boussingaultia plant, and Collinsia plants.