Written by Dr.James E. Klett
Professor Emeritus, Colorado State University, Department of Horticulture and Landscape Architecture, Fort Collins
Our three-year (two-winter) herbaceous perennial trials at Colorado State University continue to grow each year, with 106 new entries in 2023 for a total of 308 entries. Plants are evaluated for vigor, uniformity, floriferousness and tolerance to environmental and biotic stresses. The following seven perennials have been awarded the 2023 “Top Performer” award from 87 taxa planted in 2021 after performing superiorly for three growing seasons and two winters in our Fort Collins trials.
A complete report on all the perennials in the trial can be viewed at flowertrials.colostate.edu under the perennial trials menu.
Also visit the garden at 1400 Remington Street in Fort Collins, directly in front of the University Center for the Arts.
Brunnera ‘Alexandria’ from Terra Nova Nurseries
The silver cordate leaves were very attractive throughout the entire growing season. In early summer, delicate blue flowers create a unique look in the garden.
Shade, requires some moisture, useful for containers, cold hardiness Zone 4.
Tips and tricks: This plant creates dependable color in shady areas. Foliage appears thicker in substance, which creates a mat of silver leaves.
Echinacea ‘SunMagic Vintage Fuchsia’ from Flamingo Holland/Bull Breeding
The brightly colored fuchsia flowers were more horizontal with a big Hershey’s kiss cone on top, which added to its attractiveness. The dark eye and dark stems made a great contrast with the bright-colored blooms.
Sun, xeric, useful for containers, cold hardiness Zone 4.
Tips and tricks: Flowering was sustained for two solid months, and plant had very uniform growth habit and good winter survival.
Eupatorium ‘Little-Pye’ From Dümmen Orange
This plant can make a real statement in the garden. The name is kind of a misnomer because it is only little for the first year or so and then can grow to a height of 4 to 5 feet or more in the second or third year. The blooms covered the canopy in peak flowering but still remained attractive for winter interest as dried flowers.
Sun, xeric, cold hardiness Zone 3.
Tips and tricks: The plants made an excellent show in late summer and are very uniform and did not collapse or have any disease or insect problems. It was a favorite plant of the bees as well.
Heuchera ‘Big Top Caramel Apple’ from Darwin Perennials
The foliage has constantly changing colors throughout the season as it matures with various shades of caramel. Contrasting colors on the underside of the leaf create interest because it is a distinct burgundy color. Small flowers give it a more naturalized appearance, which is great for a more woodland garden.
Shade, some additional moisture, useful for containers, cold hardiness Zone 4.
Tips and tricks: Plants are vigorous, creating a large canopy with great winter survival.
Lupinus x ‘Beefeater’ from Gulley Greenhouse/Eason Horticulture Resources
The large blooms have an intense red color, which makes this a “wow” plant in any garden. The red flower color held up well in full sun, and it blooms very profusely in full sun.
Sun, some additional moisture, useful for containers, cold hardiness Zone 4.
Tips and tricks: Flower stems are strong with little to no lodging. It also keeps its foliage for a longer time in the season.
Phlox paniculata ‘Ka-Pow Soft Pink’ from Darwin Perennials
The pink flowers covered the foliage for a long season of bloom. The entire Ka-Pow series has performed well in our trials for great reliability.
Sun, more xeric, useful for containers, cold hardiness Zone 4 to 5.
Tips and tricks: Plants have excellent branching and required no pinching with good resistance to powdery mildew.
Sedum ‘Rock ‘n Grow Back in Black’ from Proven Winners/Walters Gardens
The almost black foliage makes a great contrast to the flowers with red centers and cream petals. Plant makes a nice contrast with other green foliage plants in the landscape. The late flowers makes it a great resource for sustaining pollinators late in the season.
Sun, more xeric, useful for containers, cold hardiness Zone 3.
Tips and tricks: Plant is very low maintenance and a good water-conserving choice for a more xeric garden and overall quite adaptable to multiple sites.
Colorado Green News 