Penstemon Gardening Guide: How to Grow Penstemon Plants

Penstemons, or beardtongues, are wildflowers known for their bushy shape and tubular flowers. They are part of the plantain family (Plantaginaceae) and belong to a genus (Penstemon) that contains roughly 270 species and over 800 hybrids and cultivars. As native plants of North America, they can be found all over the continent, though some varieties are native to specific regions—like California, Colorado, Arizona, New Mexico, and Utah.

Penstemon plants are drought-tolerant perennials that last year-round and come in a variety of flower colors. Penstemon flowers range in color from pastel pink and purple to bright red and blue. They also vary in size and shape, with some dwarf penstemon cultivars reaching no more than 10 inches and others growing waist-high. They are ideal flowers for gardeners looking to attract hummingbirds, bumblebees, and other pollinators. They also tend to be deer-resistant.

There are many penstemon plants to choose from, so start by familiarizing yourself with these cultivars and varieties.

1. 1. Common beardtongue (Penstemon barbatus): Native to the American Southwest, common beardtongue has showy red flowers that bloom from early summer to early fall.
2. 2. Rocky Mountain beardtongue (Penstemon strictus): Known for its bright purple flowers, Rocky Mountain beardtongue thrives in soils that most other flowering plants won’t tolerate—rocky, sandy, and gravelly.
3. 3. Pink snapdragon (Penstemon palmeri): Also known as Palmer's beardtongue, pink snapdragon features fragrant, light pink flowers and stems that can grow as much as five to six feet in height.
4. 4. Foxglove beardtongue (Penstemon digitalis): Compared to other penstemon plants, foxglove beardtongue is more tolerant of humid conditions and moist soil. Whether you get a variety with white flowers or pink flowers, they should grow at least a few feet high and bloom by May.
5. 5. Penstemon digitalis ‘Husker Red’: Known for its deep red stems, burgundy leaves, and white flowers, the ‘Husker Red’ cultivar can grow a few feet in height.
6. 6. Penstemon heterophyllus ‘Electric Blue’: Named for its bright blue flowers, the ‘Electric Blue’ cultivar grows into a small shrub, and the flowers bloom in late spring when planted correctly.

Planting penstemons can be easy as long as you keep a few tips in mind.

• Plant them in the fall or winter. Sow penstemon seeds outdoors during the late fall to early winter months so they’ll naturally germinate just in time for the growing season in late spring or early summer.
• Pick a sunny spot. Plant penstemons in a place where they can receive full sun to partial shade.
• Use well-draining soil. Choose a location with fast-draining soil. While penstemon are generally known for their hardiness, they are still sensitive to stagnant water and overly moist soil.
• Sow seeds near the surface. Bury the seeds no more than half an inch below the soil’s surface and keep them moist while they germinate. Be aware that flowers may not bloom for the first year or so.

Once you have your penstemon in the ground, plant care is fairly simple.

• Water sparingly. Many penstemon species thrive in arid climates. While they may not be as drought-tolerant as cacti and succulents, they don’t need to be watered often. Once the plants are established, only water when the top inch of soil is completely dry.
• Keep an eye out for pests. Penstemons are fairly resilient but may occasionally suffer from slugs, snails, and spider mites. You can remove these pests from the plant with a strong spray from your hose.
• Deadhead blooms occasionally. While not absolutely necessary, deadheading—or removing spent blooms—can prolong your penstemon’s bloom time and encourage new foliage to grow.

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