Gardening Season 2021
“The Annual Flower Trial Garden – also a vital training ground for CSU horticulture students – is a part of a network of trial gardens at land-grant universities nationwide,” said Jim Klett, faculty coordinator and professor in CSU’s Department of Horticulture and Landscape Architecture. “It’s the largest garden of its kind west of the Mississippi River.” Winners from the 2020 evaluation are now available at area nurseries and garden centers for the 2021 home gardening season. For more detailed descriptions and photographs, visit www.flowertrials.colostate.edu.
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 the planting and maintenance of the garden. The outcome of this research is valuable to the industry and home gardeners alike. That’s because the Rocky Mountain region has unique growing conditions, 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.
The Trial Garden receives no direct state or 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.
‘Best of’ Overall Winners
Best of Show – Dahlia ‘Lubega® Dark Velvet’ from Benary+
This was a ‘show stopper’ due to the strong contrast between the dark purple/velvet foliage and beautiful bicolor blooms. Plants were extremely attractive all by themselves with the dark foliage coloring and uniform compact growth habit. The prolific flowers were held high above the plants to create maximum show. Blooms had single petals which attracted many bees. Plants did not have any sign of powdery mildew even late in the season.
Best Novelty – Colocasia ‘Heart of the Jungle™’ from Proven Winners
This plant makes a dramatic statement to any landscape with its large, dark foliage. The impressive size and shape create a very tropical and exotic appearance. It is grown for the beautiful foliage which makes a great structure plant in the garden. It does best in full sun.
Best New Variety – Centaurea ‘Snowy Owl’ from Terra Nova® Nurseries, Inc.
Unique silvery foliage made this plant a standout in the garden. Large, velvety leaves added an interesting textural element. The beautiful gray color made a great combination with other plants. It was highly visible in the garden and very uniform.
Best Container – Petunia ‘Bee’s Knee’ from Ball FloraPlant
The abundant flowers and great two-tone yellow color provided exceptional flower power on very vigorous and well-branched plants. It was noted for having the best yellow of any petunia in the trial. The color held up very well in the high light intensity of Colorado.
‘Best Of’ by Class
Angelonia (container) – ‘Serenita® Pink’ from PanAmerican Seed
Masses of beautiful spikes of pink flowers filled the container while maintaining a very uniform appearance all season. The bicolor flowers were an attractive combination of pink with a dark burgundy eye.
Angelonia (ground) – ‘Archangel™ Raspberry’ from Ball FloraPlant
Rosey-pink flowers were very abundant and made a very attractive show. They seemed to jump forward towards the viewer. Blooms were large and plants were of medium height. Uniform plants were described as having a good “roundy, moundy” growth habit. Overall, these plants had great vigor and were very low maintenance.
Begonia (container, vegetative) – ‘Dreams BK Collection Vermillion Red®’ from Beekenkamp Plants
The intense red flowers almost glowed in the shade. The multiflora cluster of flowers gave the impression of a really large bloom. Plants were vigorous and had attractive dark green foliage. This was a repeat winner from last year and noted as a dependable performer.
Begonia (container, semi-trailing, vegetative) – ‘Solenia Red®’ from Beekenkamp Plants
The plant was noted for its prolific blooming and gorgeous red flowers. It was described as being “tough as nails” for its ability to continually bloom throughout the heat of the summer. It looked great in a container but reported to do well in the ground also.
Begonia (container, seed) – ‘BIG Bronze Leaf Deep Rose’ from Benary+
Vigorous plants had large foliage and large blooms. The vibrant flower color popped exceptionally well in contrast with the deep bronze/green of the foliage. Plants were noted to have good uniformity.
Calibrachoa – ‘Cha-Cha™ Frosty Lemon’ from Ball FloraPlant
Large, bicolor flowers were a beautiful combination of soft primrose with a deep yellow throat. Plants featured good foliage and a nice tight growth habit. Vigorous plants produced abundant flowers and lots of color.
Celosia (container) – ‘Sol™ Lizzard Leaf’ from Pan American Seed
This plant looked good both in a container and in the ground. The glossy foliage was unique and would look great in a mix combo container. The foliage was darker in full sun. Grown mostly for the foliage, the flowers were considered mostly a bonus but they added considerable interest with a unique crested shape.
Celosia (ground) – ‘Bright Sparks™ Burgundy’ from Syngenta
The huge, rich red flowers stood out from all the other celosias. The flower size and color were very impressive but the prolific blooming added to the impressive show. Plants were uniform but also very attractive by themselves with very attractive burgundy foliage.
Coleus (container) – ‘Main Street Beale Street’ from DummenOrange
A multi-year winner due to its rich, velvety burgundy leaf color which provided color to the garden all season long. Plant vigor was excellent while also maintaining a very uniform growth habit. Flowers were virtually non-existent. Plants performed great in both the ground and containers.
Coleus (ground) – ‘FlameThrower™ Cajun Spice’ from Ball FloraPlant
The foliage was noted for a “crazy” leaf pattern and a showy golden/green edge. Plants had controlled vigor that resulted in a very uniform growth habit. The overall appearance was attractive and plants did not have any flower spikes.
Combination – ‘Kwik Kombos™ Pink Lemonade Mix’ from Syngenta
The overall appearance of this combo was very vibrant. It was also impressive that all three components looked great together. Plants had good vigor and a good trailing habit over the side of the container. It was a dependable performer in past years as well as in 2020.
Dahlia – ‘Lubega® Dark Velvet’ from Benary+
This was a ‘show stopper’ due to the strong contrast between the dark purple/velvet foliage and beautiful bicolor blooms. Plants were extremely attractive all by themselves with the dark foliage coloring and uniform compact growth habit. The prolific flowers were held high above the plants to create maximum show. Blooms had single petals which attracted many bees. Plants did not have any sign of powdery mildew even late in the season.
Geranium (interspecific) – ‘Calliope® Large Dark Red’ from Syngenta
Another dependable performer as it has been a multi-year winner and still leads the pack. Flowers were a very impressive dark, rich shade of red with a lot of flower power. The plant had great vigor that was great in the landscape but also good for containers.
Geranium (zonal) – ‘Super Moon Red’ from Selecta One
The rich red flower color was a standout in that it did not wash out in the intense sunlight. Plants were very vigorous and uniform with an excellent overall appearance. Blooming was strong throughout the season. The foliage had nice zonation.
Impatiens – ‘Beacon® White’ from PanAmerican Seed
Abundant, clear white blooms covered the plants which really brightened up a shady location. Dark green foliage helped make the flower color even more bright. Plants had a very uniform growth habit and had the added plus of being disease resistant to downy mildew.
Lantana – ‘Hot Blooded™ Red’ from Syngenta
Vibrant flowers had at least 3 different colors that ranged from deep red to tangerine. Plants had a beautiful and uniform growth habit with abundant flowers on top of plant producing a lot of flower power.
Lobelia – ‘Glow™ White Lightning’ from Danziger
Vigorous plants combined with prolific flowering that continued throughout the heat of a record-setting summer. The abundant white blossoms were on plants that maintained great uniformity.
New Guinea Impatiens – ‘SunPatiens® Vigorous Lavender Splash’ from Sakata
Dark green foliage made a great flower to foliage contrast that helped make the lavender flowers really stand out. Plants were vigorous but maintained an attractive and uniform growth habit.
Pentas – ‘BeeBright™ Violet’ from Syngenta
Flowers lived up to their name with abundant violet flowers that were a favorite of the bees. Plants were noted to be superior due to uniform, compact growth habits and dark green foliage.
Petunia (container, vegetative) – ‘SuperCal® Royal Red’ from Sakata
Blooms were a fantastic dark cherry color which impressed the evaluators with “stop in your tracks” flower power. The color was held even as the flowers faded. Plants were very vigorous and were well branched which resulted in an excellent growth habit.
Petunia (ground, vegetative) – ‘ColorRush™ White’ from Ball FloraPlant
Large flowers were a good clean white color and very abundant. Plants were vigorous, uniform and had excellent flower power.
Petunia (ground, seed) – ‘Easy Wave® Violet’ from PanAmerican Seed
Violet flowers covered vigorous plants that had a great spreading growth habit that resulted in a vibrant blanket of blooms. Plants held up well under adverse conditions and maintained good uniformity even with some shade.
Portulaca – ‘ColorBlast™ Double Orange *2’ from Westhoff
Showy flowers were noted for vivid shades of orange and double petals. Plants were vigorous and had excellent uniformity.
Salvia – ‘Mystic Spires’ from Ball FloraPlant
Dependable flowering and great growth habits made this a winner both in 2020 and in previous years. Vigorous plants were stately and upright with abundant dark purple flowers. The foliage was clean and glossy. This was another bee-friendly plant that was often buzzing with excitement with pollinators.
Scaevola – ‘Abanico Power Laguna Blue’ from Benary+
Plants had impressive vigor and produced large flowers that covered the plants. The showy, blue blooms held their color and were weather resistant. This entry was grown in a container but would work well in the ground.
Thunbergia – ‘Sunny Susy® Yellow Dark Eye’ from Benary+
The vigorous plants made great climbers and were perfect for either a trellis or hanging basket. Flowers were a very vibrant lemon yellow with a nice dark brown throat for added contrast.
Verbena (container) – ‘Estrella™ Blueberry Improved’ from Westhoff
The big, blue flowers stood out against the dark foliage for an impressive overall appearance. The semi-trailing habit worked well in containers but would also do well in the ground. Plants were bred for mildew resistance and looked clean all season.
Verbena (ground) – ‘EnduraScape™ White’ from Ball FloraPlant
The plant would be great for landscapes due to vigorous growth, large plants and mammoth blooms. Showy, white blooms paired well with many other garden plants. Plants ‘buried their dead’ blooms to keep a fresh appearance all season.
Vinca (container) – ‘Valiant™ Pure White’ from PanAmerican Seed
Flowers lived up to their pure white name and the large blooms created a lot of flower power. Plants were vigorous, well-structured and filled the container. The glossy, dark green foliage made a good contrast with the white blooms.
Vinca (ground) – ‘Virtuosa Lavender’ from Sakata
Plants were vigorous and produced abundant large, soft lavender flowers that had a white eye for added interest. The compact and uniform plants did well in the ground but would probably also look great in a container.
Zinnia (container) – ‘Preciosa™ Orange’ from American Takii
Bright, clear orange flowers eventually faded to an attractive gold color but were fully double and very prolific. Plants were bred to be more compact with superior branching and they filled the container producing excellent flower power.
Zinnia (ground) – ‘Magellan™ Orange’ from Syngenta
Large orange flowers were very prolific and very showy. Plants were vigorous, sturdy and did not lodge with overhead watering. The overall appearance was impressive with the vibrant color and uniform growth habit.
Evaluation
The trial evaluation week was held on August 3-7, 2020. Approximately 100 judges consisting of industry representatives, master gardeners, university employees and trial garden advisory committee members evaluated the plant varieties for performance using a combination of these criteria:
Plant Quality:
- Uniformity of plant habit
- Bushy, well-branched shape versus open and leggy
- Healthy foliage (deep green versus chlorotic, yellow leaves)
- Foliage texture
- Disease resistance
Flower Quality:
- Flower power (number of flowers per plant, substance and holding power)
- Flower presentation (i.e. not hidden by the foliage)
- Color uniformity
- Stable color (resistance to fading) and stable pattern (for bicolor)
- Flower size and uniformity of flowers
- Balance of color in a mixture
Overall Presentation:
- Overall “clean” look, versus visible spent blooms
- Fragrant flowers and/or foliage
- Good vigorous growth
- Resistance to climatic stress
- Novelty value of unique features
- Overall consumer appeal
Plant varieties were rated on a scale of 1 to 5 (1 = very poor performance; 5 = excellent performance). These numerical evaluations were used to calculate the average ratings for each variety in the trials. Participants were to use their tablets or cell phones to electronically evaluate the plants. The pre-generated comments they could choose from included: Low vigor, Vigorous plant, Few flowers, Many flowers, Uniform, Non-uniform, Unique color, and Some chlorosis.
Selection of “Best Of” Winners and “Other Outstanding Plants”
Ratings from all evaluators on August 3-7, were averaged and the top five in each class were placed on a preliminary list. A class is determined to be any group of plants in the same genus that consisted of 10 or more trial entries. The “Best Of” award was given to classes whose top-five list had ratings of at least 3.0 and one of them could be considered superior. A sub-committee of the university and industry representatives revisited the garden on September 11th to review the top-five list and verify the superiority of the top-rated varieties later in the season and not just on August 3-7. A majority vote was taken for each class to determine the final selections for winners. The following is a list of the 2021 “Best Of” Annual Flower winners and the complete list and report can be found at www.flowertrials.colostate.edu.