CSU Perennial Trial Program By CSU Horticulture Agent, Linda Langelo
According to Jim Klett, Professor, Colorado State University, Department of Horticulture and Landscape Architecture for three summers and two winters, CSU trials new varieties of perennials from the last 3 years. The plants are evaluated by their performance under Rocky Mountain environmental conditions. The perennials are evaluated for plant vigor, uniformity, floriferousness and tolerance to environmental and biotic stresses.
Here are the top performers:
Allium ‘Summer Beauty’ (Allium lusitanicum) from Stonehouse Nursery, LLC
This was a strong bloomer even in late summer. The foliage did not lodge, had good structure and the plants were uniform.
Echinacea ‘Sombrero® Tres Amigos’ (Echinacea x hybrida) from Darwin Perennials
Plants showed good branching and no disease with long blooming flowers that demonstrated three different shades of the same color.
Penstemon ‘DAKOTA™ Burgundy’(Penstemon digitalis) from Terra Nova Nurseries
The burgundy foliage was one of the primary reasons for a high rating besides long blooming period. The plants were very showy due to the foliage. They also had a 100% survival rate over three seasons.
Phlox‘Ka-Pow®’ series (Phlox paniculata) from Darwin Perennials
Evaluators were impressed with the entire series as all had similar height, were very uniform and resistant to powdery mildew. Flowers had a long period of bloom with no color fade. Series had a range of colors that went from soft lavender to a vibrant pink. The pink entry was noted to have some shades of coral which is unique to Phlox.
Salvia ‘Blue by You’(Salvia nemerosa) from Darwin Perennials
Vibrant blue flowers were very showy with prolific amounts of blooms early in the season and an impressive repeat later in the season after a hard cut back of old blooms. The unique blue color is a great addition to the pallet of Salvia colors in the trade and evaluators said they “had to go see it” from across the garden.