Penstemon ‘Dark Towers’ (Beardtongue)

Penstemon ‘Dark Towers’ is a hybrid penstemon that combines the strong pink flowers of Penstemon ‘Prairie Splendor’ with the dark foliage of Penstemon digitalis ‘Husker Red’. Its striking appearance comes from its deep burgundy foliage contrasted against its light pink tubular flowers.

Penstemon ‘Dark Towers’: An In-depth Look

Native: Similarly to its parents, Penstemon ‘Prairie Splendor’ and ‘Husker Red’, this hybrid was developed by the University of Nebraska.

Plant Type and Habit: This semi-evergreen perennial has a bushy, upright habit. It exhibits clumping growth, making it an attractive border plant or a stand-alone centerpiece in a garden.

Size: Typically, Penstemon ‘Dark Towers’ typically grows to a height of 24-36 inches (60-90 cm) and spreads approximately 30 inches (75 cm) wide.

Flowers: Penstemon ‘Dark Towers’ boasts tubular, soft pink to pale lavender flowers arranged in airy spires. They rise above the dark burgundy foliage and provide a dramatic visual effect.

Bloom Time: The blooming period for ‘Dark Towers’ is relatively long, beginning in early summer and often extending into early fall.

Foliage: Its semi-evergreen foliage is perhaps its most striking feature, with leaves of a deep wine-red to burgundy color, darker than its parent ‘Husker Red’.

Uses: It’s used primarily for ornamental purposes due to its striking foliage and attractive flowers. It’s perfect for borders, mass plantings, or as an accent plant in city gardens, coastal gardens, rock gardens, cottage gardens, rain gardens or prairie plantings. Good as cut flowers, too!

Pollinators: Penstemon is attractive to various pollinators, especially bees, and hummingbirds, which are drawn to their nectar-rich flowers.

Toxicity: Penstemon ‘Dark Towers’ isn’t known for being toxic to humans or pets, but it’s always good practice to prevent ingestion and maintain supervision of pets and young children in any garden setting.

Deer and Rabbit: Deer tend to avoid ‘Dark Towers’, and while rabbits might show interest, its coarse leaves aren’t their first choice.

Drought: Once established, ‘Dark Towers’ has a good level of drought tolerance, making it suitable for xeriscaping.

Penstemon Growing Tips

Light: Full sun (at least 6 hours of direct sun per day).

Soil: Fertile, well-drained loams, clay loam, sand soil. Avoid overly moist, poorly drained soils.

Water: Water well until plants are established. Once established, this Penstemon tolerates occasional drought and flooding. Allow the soil to dry out between waterings. Over-watering or wet soils can lead to root rot.

Fertilizer: Penstemon plants generally do not require heavy fertilization and can thrive in relatively lean soil conditions. However, providing them with a light application of an organic fertilizer in the fall can help boost their growth and flowering potential.

Pruning: Deadhead spent flowers to encourage continuous blooming. Cut back plants in late autumn or early spring to promote vigorous growth.

Mulching: Mulching Penstemon can help regulate ground temperature and suppress weed growth. Choose a mulch that does not hold water. Use organic materials like shredded bark, compost, or pine straw. Avoiding direct contact with the stems to prevent rot and pest issues.

Propagation: Propagate by softwood cuttings in early summer, semi-hardwood cuttings in midsummer, or by division in spring

Pests and Diseases: No serious pest or disease issues, but watch for slugs, snails, and nematodes. Fungal diseases can occur in overly wet conditions; ensure good air circulation and avoid overhead watering to prevent issues like powdery mildew, leaf spot, and root rot. Rust can cause small, rust-colored pustules on leaves and stems, leading to defoliation and stunted growth.