The Colorado State University Department of Horticulture and Landscape Architecture conducts plant trials each year to weed out poor performers and determine best bets for gardeners in the Rocky Mountain region.
CSU added new herbaceous perennial trials to their longstanding trials of annual flower trials. Perennials make good sense for your garden because these plants return year after year, getting better and better, given the proper growing conditions. If you're planning to plant perennials in your Front Range garden, CSU has done the homework for you.
"These herbaceous perennial trials have been conducted for the past six years to evaluate the performance of newer herbaceous perennials in the High Plains and Rocky Mountain region," said James Klett, CSU Professor and Extension Landscape Horticulture Specialist.
"Colorado State University is very unique in the United States conducting these two-year herbaceous perennial trials," said Professor Klett.
CSU provided the following list of “Top Performers" herbaceous perennials:
• Buddleia davidii ‘Buzz™’ (Buzz™ Butterfly Bush series) - from Pacific Plug and Liner
The entire ‘Buzz’ series was noted for their excellent flower production and dense growth. The range of colors in this series was: Blue Violet, Ivory, Pink Purple, Violet and Magenta. Judges noted that all in the series were exceptional, but agreed that the ‘Magenta’ was their favorite. ‘Magenta’ had a vivid eye catching color that was unique to any other Buddleia out on the market. Compact plants would work well as a mixed border plant. Bred by Thompson & Morgan.
• Helleborus x ballardiae ‘Gold Collection®’ series, (Gold Collection® Lenten Rose series) - from Skagit Gardens
The two plant varieties in the ‘Gold Collection®’ series were both praised for their early blooms in March. ‘Cinnamon Snow’ had flowers with a deep pink blush with a yellow interior and ‘Pink Frost’ had flowers with a light pink blush on chartreuse petals. Judges noted that plants held their flowers facing more upright toward viewers than other Helleborus. The dark green glossy foliage looked great all year long in Colorado’s low humidity. Plants would be a wonderful groundcover for a shady area.
• Monarda ‘Fireball’ (Fireball Bee Balm) - from McGregor Plant Sale
Plants were prolific bloomers in July with wine colored blooms. Plants were sturdy with no lodging even with overhead irrigation. Judges noted that ‘Fireball’ had superior mildew resistance than other Monarda. Vigorous plants would be great for the back of a perennial border. Bred by Hubertus Gerardus Oudshoorn.
• Phlox paniculata ‘Classic Cassis’ (Classic Cassis Perennial Phlox) - from McGregor Plant Sales
‘Classic Cassis’ had a long bloom time with their big bold flowers. Blooms that were bright pink with hints of mauve started in June and continued through August. Plants had nice green foliage that stayed clean throughout season.
• Phlox paniculata ‘Pina Colada’ (Pina Colada Perennial Phlox) - from McGregor Plant Sales
Flowering was robust from late June through September and the showy blooms had overlapping, pure white petals. Plants were impressive with exceptional dark green foliage and uniform compact growth habit. Spent flowers dropped off the flower panicles and gave plants a clean look throughout the season. It was bred by Jan Verschoor, Holland.
• Anemone ‘Pretty Lady Diana’ (Pretty Lady Diana Windflower) – from Blooms of Bressingham
Plants were very floriferous with deep pink blooms in August through September. ‘Pretty Lady Diana’ had compact uniform growth habit. Judges mentioned that the plants would not take up a lot of space and would be great for a small garden or in a mix border. Bred by Yoshihiro Kanazawa.
• Baptisia Decadence TM ‘Lemon Meringue’ (Lemon Meringue Baptisia) – from Walter’s Gardens/ Proven Winners
Early blooming plants showed off their yellow blooms in May. Judges mentioned that the blooms have a clear crisp flower color that is unique to Baptisia. Even though blooms were brief the plants had an open airy habit and nice foliage to enjoy the rest of the season.
• Echinacea ‘Balsomsed’ (Sombrero TM Salsa Red Coneflower) – from Darwin Perennials
Compact plants had superior branching that filled up nicely after only one winter. Each plant was packed with lots of hot red flowers. Judges noted that the plants were very floriferous with a long season of bloom. The red flowers held its color for a long time making it quite a show. Bred by Jianping Ren.
• Geranium ‘Eureka Blue’ (Eureka Blue Cranesbill)- from Blooms of Bressingham
Bright violet flowers were on plants from late May through July. Judges mentioned that although this variety is ‘ultra vigorous’ it holds up its shape through the growing season. Plants had healthy foliage all season long. Bred by Brian Kabbes.
• Hibiscus Summerific TM ‘Cranberry Crush’ (Cranberry Crush Rose Mallow)- from Walter’s Gardens/ Proven Winners
Deep red blooms started in July on uniform plants. The glossy leaves were deeply lobed and had an attractive dark red hue. Judges noted that these plants gave the garden a dramatic tropical effect. Plants would be great for late summer color in the back of a border. Bred by Clarence H. Falstad.
• Nepeta ‘Novanepjun’ Junior Walker TM Catmint) - from Conard-Pyle Co
Vigorous plants bloomed all season long with bright lavender flowers. Judges mentioned that plants were a great intermediate size at the size of 24 inches in height and 32 inches in width. Plants filled in the space quickly making a great ground cover. Bred by Michael S. Dobres.
To learn more about ‘Top Performer’ Herbaceous Perennial Winners in CSU's 2012 trials go to www.flowertrials.colostate.edu. Click on the "Trials" tab and then select "Perennials." The website also includes photos and the complete 2012 Trial Report.
The herbaceous perennial trials were conducted at the Annual Flower Trial Garden, located in front of the University Center for the Arts, at 1401 Remington Street in Fort Collins.
"Our trial garden is open to the public, making it an excellent venue for students, industry personnel and homeowners to view and gather ideas about new perennial plant varieties," said Professor Klett.
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