Penstemon x mexicali Red Rocks (Beardtongue)

Penstemon x mexicali Red Rocks is a stellar hybrid, celebrated for its profusion of vibrant, trumpet-shaped, cerise-pink flowers. It’s a robust, floriferous perennial that adds a splash of color to any garden setting.

Penstemon x mexicali Red Rocks is a gem for any garden, encapsulating beauty, resilience, and environmental support in one package. Its easy-care nature combined with its ornamental and ecological value makes it a favored choice for both novice and experienced gardeners.

Penstemon x mexicali Red Rocks: An In-depth Look

Native: Red Rocks is a hybrid variety, a cross between Mexican and American Penstemon species, thus called Penstemon x mexicali. It inherits hardiness from its American parentage and vibrant colors and extended blooming periods from its Mexican ancestors.

Plant Type and Habit: This perennial exhibits a mounding habit with upright flower spikes. It’s a clump-forming plant that maintains a compact shape, making it suitable for border fronts, rock gardens, or container plantings.

Size: Red Rocks typically grows to a height of 12-34 inches (30-90 cm) and spreads around 18-24 inches (45-60 cm), creating a clump mat of foliage and flowers that’s visually appealing without being overly expansive.

Flowers: The flowers are undoubtedly the star feature, presenting a brilliant cerise-pink hue that’s a magnet for the eyes and wildlife alike. Their trumpet shape is characteristic of Penstemons, contributing both form and long-lasting color to gardens.

Bloom Time: One of its notable attributes is the extended blooming time, which spans from late spring until early fall, much longer than many traditional Penstemon species.

Foliage: The foliage of Red Rocks is a lush, deep green with a lanceolate shape. Leaves are arranged oppositely on the stem, creating a dense foliage mound that remains attractive even when the plant is not in bloom.

Uses: Ideal for perennial borders, rock gardens, containers, or mass plantings. Its extended bloom time and vibrant color also make it a favored choice for ornamental displays and pollinator gardens.

Hardiness: Red Rocks is known for its exceptional hardiness, tolerating cold well in USDA zones 5-8.

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

Toxicity: Penstemons are not known to be toxic to humans or pets. However, it’s always prudent to prevent ingestion of any non-edible plants.

Deer and Rabbit: An added bonus is its resistance to deer and rabbits, a characteristic attributed to the texture and taste of the foliage that these animals generally find unappealing.

Drought: Once established, Red Rocks boasts a high drought tolerance, thanks to its hybrid vigor and the drought-resistant traits it inherits from its Mexican Penstemon lineage.

Invasiveness: Red Rocks is not known to be invasive. It will spread within its designated space in the garden but doesn’t aggressively encroach on the areas of other plants.

Penstemon Growing Tips

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

Soil: Well-drained soil is crucial. Penstemons prefer rocky or sandy lean soils rather than rich garden loam. Avoid overly moist, poorly drained soils.

Water: Water well until plants are established. Once established, Penstemons tolerate some drought. 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 or semi-ripe cuttings in midsummer.

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.