Rydberg's Penstemon (Penstemon rydbergii) is a beautiful blue penstemon that emerges in the spring as a green basal rosette. This is followed by an upright stem topped with purple/blue blossoms in the early summer. What sets this penstemon apart from other common Utah penstemons, is the blossoms are arranged on the stem in dramatic whorls. This longer-lived and showy perennials usually appears in moist meadows with other native flowers and grasses and will require supplemental irrigation in dry valley areas. Plant in naturalistic prairie or meadow gardens, cottage gardens, regular garden beds or borders, on the sunny edges of shade or woodland gardens, or rain gardens.
Rydberg's Penstemon
Irrigation Requirement: Low (1/2" every 10-14 days) to Moderate (1/2" every 7-10 days)
Mature Size: 1 - 2' tall and wide
Spacing: 1-2'
Bloom Colors: Purple, blue
Bloom Season: May - July or August
Hardiness Zone: 4 - 9
Light Requirement: Full Sun (preferred) to Partial Shade
Deer Resistant: Yes
Salt Tolerant: No
Soils: Grows in sandy, loam, or clay soils that are well-draining.
Plants in the Penstemon genus are host plants for up to 19 different species in northern Utah. Rydberg's Penstemon is also a nectar source for a wide range of polliantors, including hummingbirds.