Perennial Trials reveal top 10 performers in Rocky Mountain conditions

Note to Reporters: Photos of the top performers are available at http://source.colostate.edu/perennial-trials-reveal-top-10-performers/

After three seasons growing in the challenging conditions of the Rocky Mountains, 10 perennial plants have been named "Top Performers" by researchers at Colorado State University.

From anemones to salvias, these plants have shown they have what it takes to bloom and thrive year after year.

Nearly 40 years ago, Colorado State University established the W.D. Holley Plant Environmental Research Center on the school’s Fort Collins campus, with trial gardens prepared to evaluate annual and perennial selections. In 2007, additional perennial trials were created adjacent to the annual flower trials in response to increased interest in new perennial cultivars.

Evaluating perennials in the Rocky Mountains

The purpose of the trial garden is to evaluate perennial plant species and cultivars under the unique Rocky Mountain environmental conditions. Colorado’s growing conditions are characterized by high altitude, intense solar radiation, drying winds, severe hailstorms, large fluctuations between day and night temperatures and a season-long need for irrigation. Plants are evaluated for plant vigor, uniformity, floriferousness and tolerance to environmental and biotic stresses.

For the “Top Performer” winners of 2014, selections were planted in 2012, requiring that they perform through two winters and three growing seasons. Data (ratings and photos) were collected every two weeks (May to early October) by the student coordinator. Plants were evaluated once a month by members of the Perennial Trial subcommittee. The Perennial Trial subcommittee met in October to review data and photos to vote on which entries should be designated a “Top Performer.” The following is a list of the 2014 winners.

“Top Performer” of Perennials

Blue Boa Agastache from Terra Nova® Nurseries (Agastache x hybrida ‘Blue Boa’PP24050)
Non-stop flower power resulted in a season long splash of bright lavender color that covered the plant in blooms from top to bottom. Excellent vigor and a relatively large growth habit would make this a good choice for the back of a perennial border that needs color. Besides all the beauty, this plant is also recommended for its drought tolerance and ability to attract bees and butterflies. This entry was also given the “Too Good to Wait” award in 2013. Planted in 2012.

Leilani Coneflower from Terra Nova® Nurseries (Echinacea spp. ‘Lelani’ PP23526)
Tall, vigorous plants “wowed!” visitors with the prolific display of “warm, buttery yellow” flowers. Blooming occurred over a long period and the plants maintained superior controlled vigor for good uniformity and overall appearance. Planted in 2012.

Profusion Coneflower from Eason Horticultural Resources (Echinacea purpurea ‘Profusion’)
Flowers had a unique appearance and overall shape due to many petals with a nice shape and a large, dark center. The dark stems also complemented the flower petals and dark center. Plants were compact but flowering was very profuse and lived up to its name. The light lavender petals also faded nicely into a “antique” lavender color that was also very attractive and extended the bloom time. Planted in 2012.

Georgia Plum Coral Bells from Terra Nova® Nurseries (Heuchera x hybrida ‘Georgia Plum’PP24507)
Plum colored foliage was impressive all season and did not show any signs of fading. Besides the plum color, foliage also had a nice silver sheen for good color impact throughout the growing season. Plants were very uniform and had excellent growth habit. Predominantly grown for the foliage, the light pink/plum flowers were few but still attractive. Planted in 2012.

Midnight Marvel Hibiscus from Walters Gardens/ Proven Winners® (Hibiscus x hybrida ‘Midnight Marvel’PP24079)
The flowers and foliage made a spectacular combination. Dark bronze foliage made a perfect backdrop to the beautiful flowers with a rich, red color. Many flowers came into bloom together and created a good visual impact. Plants were vigorous but maintained a nice size without getting too large as observed in some other Hibiscus. Planted in 2012.

‘Too Good To Wait’ Performer for the 2013 Season

Class of 2013 Grown in 2014 (1 winter)
This category is to acknowledge an upcoming plant that has been in the ground one winter and two growing seasons and has shown excellent performance thus far in the trial. The Perennial Trial Committee likes to award “Top Performer” to plants that have been in the ground two winters and three growing seasons. This plant impressed the Perennial Trial Committee so much that they designated the category name: “Too Good to Wait Performer.”

Electric Avenue Coreopsis from Creek Hill/Eason (Coreopsis verticillata ‘Mayo Clinic Flower of Hope’PPAF or ‘Electric Avenue’)
Bright yellow flowers were very showy and flowering was solid all season. Plants were vigorous, uniform and maintained good stature from spring to fall. Fine textured foliage and a nice flower shape contributed to a very pleasing overall affect. This is good plant for attracting bees. Overwintering survival was impressive with no losses despite a difficult winter in Fort Collins, CO during 2013-2014.

Beyond Blue Fescue from Skagit Gardens (Festuca glauca ‘Casca11’ PP#23307)
This fescue is considered to have the best “blue” color out there! Plants are larger than Feetuca ‘Boulder Blue’ but maintain a nice “ball” shape and do not open in the middle. Flower stems fade and disappear amongst the foliage for a superior appearance. This is an improved variety over older ones for foliage color.

Sunrosa™ Red Rose from Suntory® Flowers (Rosa x hybrid Sunrosa™ Red)
Constant red flowers and impressive growth habit make this plant attractive all season. Glossy dark green foliage had no signs of chlorosis or disease. Red flowers did not fade and bloomed steadily from mid-June through October. Small foliage and a dwarf compact growth habit make this a good choice for the smaller or mid-size landscapes. The compact growth habit is maintained without any pruning.

About the Trial Garden
CSU’s Flower Trial Garden, which draws thousands of visitors each year, relies on student gardeners, volunteers and industry supporters and experts who help provide detailed analysis of plant performance. Colorado State Extension Master Gardeners play an essential role in planting and maintenance of the garden. The outcome of this research is valuable to the industry and home gardeners alike. The Trial Garden receives no direct public funding. It is funded primarily by fees from plant-breeding companies that submit entries to the trials. The garden also receives donations from industry associations, foundations, nurseries, plant producers and other companies in the green industry.

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