CSU Research: “Top Performer” Perennials from the 2022 CSU Flower Trial

In 2022, Colorado State University continued its three-year herbaceous perennial trial and chose eight perennials as the ‘Top Performers’ from 113 that were planted in 2020. A CSU Top Performer has to have great survival percentages after two winters and three growing seasons and score excellent throughout the three growing seasons. A subcommittee of the CSU Annual Trial Committee evaluated 21 of the top performing perennials in November 2022 by examining photos of these plants taken every two weeks during the three growing seasons. A majority favorable vote from the committee was needed for a perennial to become a CSU Top Performer.

Perennials that earned this description have proven to be adaptable to the Front Range in Colorado. The following eight plants were awarded Top Performer for 2022. Hopefully many of you will start to grow, sell and utilize these plants in Colorado landscapes.

A complete report on the perennials in the trial can be viewed at www.flowertrials.colostate.edu under the Perennial Trials tab.

1. Armeria Dreameria® – ‘Dream Clouds’ Sea Pinks from Darwin Perennials

This Armeria has been bred to provide a long season of bloom with pure white flowers giving it a crisp, impressive appearance. The mounded growth habit makes it perfect for landscapes or patio containers.

2. Leucanthemum Sweet Daisy™ – Rebecca
Rebecca Shasta Daisy from Dümmen Orange

The blooms are a stunning white with multiple layers of petals with a yellow eye. Flower petals have a frilly edge that is quite different from your normal Shasta Daisy. Plants had a compact and tidy growth habit.

3. Phlox paniculata Early® Magenta
Early Magenta Garden Phlox from Dümmen Orange

This garden phlox has a compact, uniform growth habit with a solid wall of magenta flowers. It had exceptional flowers early and late into the season, and has good mildew resistance.

4. Phlox paniculata Ka-Pow® White
Ka-Pow® White Garden Phlox

These plants were more compact, uniform and sturdy and maintained an excellent habit despite overheard watering. Branching was very good which created an abundance of crisp, white flowers that were very showy. Foliage was very attractive and never had any powdery mildew.

5. Phlox subulata Spring® Blue Improved
Spring Blue Improved Creeping Phlox from Dümmen

Growth habit makes this plant an excellent ground cover that spreads evenly. The season of bloom for this creeping phlox was noted for being exceptionally long and plants looked good all through the summer.

6. Rosa Petite Knock Out® Meibenbino
Meibenbino Knock Out Rose from Star Rose and Plants

This rose is in a class of its own with very beautiful, glossy foliage and petite growth habit. Flowers had a dark saturated red color that make a striking combination with glossy dark green foliage.

7. Salvia nemorosa ‘Midnight Purple and Midnight Rose’
Midnight Purple and Midnight Rose from Dümmen

The midnight series includes compact, very uniform salvias with darker stems and flowers. Growth habits were very uniform with very even heights.

8. Thermopsis lupinoides – Golden Candles from Plant Select®

When at its peak in spring, the stunning yellow flowers are a real showstopper. The lupine-like foliage is lush and attractive along with being a nitrogen fixer for the soil.