Steve Poppe, Horticulture Scientist (retired), Nate Dalman, Horticulture Researcher III, and Esther Jordan, Communications Specialist
Each year, hundreds of annual flowers are on public display as part of the annual flower variety trial at the University of Minnesota West Central Research and Outreach Center (WCROC) Horticulture Display Garden in Morris, MN.
In 2021, we trialed over 500 varieties ranging from ageratum to lantana to petunias to salvia, representing plant breeding companies from around the world. Even though the annual flowers are under evaluation, each cultivar is carefully designed into a beautifully landscaped garden bed, which allows visitors to take note of their favorite varieties under regional conditions. Cultivars are grown from seed or are vegetatively propagated in our greenhouse, and later transplanted into the Horticulture Display Garden.
Planting of the 2021 annual flower trial began in late May. A few days after planting, we experienced unseasonably overnight low temperatures resulting in severe cold injury on the less cold tolerant plants. Then, within a week, we had abnormally daytime high temperatures nearing 100 degrees Fahrenheit. This swing in extreme weather significantly set the growth of the plants back for several weeks following planting. Throughout this growing season, we have experienced extreme drought conditions - little to no precipitation and high temperatures, which has stressed the plants even though they were irrigated.
Despite these challenges, most of the annual flowers bounced back and offered an impressive display of color during their peak season, which is typically from mid-July to early-September.
As part of the annual flower trial, plants are evaluated up to five times during the growing season in order to assess each variety’s performance. We use a 1 to 5 scale for providing a horticultural rating (1=poor, 2=below average, 3=average, 4=above average, 5=excellent). Plants are rated on performance, color, vigor, uniformity of habit and flowering, flowering numbers relative to others, insect and disease resistance, and uniqueness. The data is taken by the same individual every time to reduce variability in scoring. Evaluations began 3 weeks following planting. Only the highest rating cultivars earn the distinction of a Top Ten Performing Annual recommendations for Minnesota. See a complete list of all trial results.
2021 Top Ten Performing Annuals
Angelonia Angelissa™ Rose Also known as a “Summer Snapdragon”, Angelissa™ Rose featured large flower spikes and strong sturdy stems, making it a worry-free performer all season long. Grew to a height of 12 to 16 inches in partial sun to full sun. Besides the outstanding rose flower color, the foliage remained bright green throughout the entire summer.
Begonia x benariensis BIG® White Green Leaf is a hybrid seed-grown wax begonia. It offers large showy flowers atop glossy foliage that covered the plant throughout the summer. Performed well in a large container in either sun or shade.
Begonia BK Collection Vermillion Red flowered relentlessly all summer long with numerous, eye-catching rich and deep dark-red double blooms with clean dark green foliage. Performed exceptionally well in a semi-shaded pergola and required no plant maintenance. Best grown in a hanging basket.
Calibrachoa Bloomtastic Yellow Out of the nearly 15 calibrachoa we trialed in 2021, this was a fan favorite! The plant was covered with attractive extra-large yellow flowers throughout the growing season. This semi-trailing Calibrachoa proved to have excellent garden performance and grew evenly and uniformly in a large hanging basket.
Celosia Kelos® Fire Orange has an upright growing habit with good plant vigor. It had an abundance of striking orange plumed flowers, making it a stand-out in our retaining wall garden bed. For us, it grew best in full sun in a very warm planting bed with well-drained soil. Kelos™ Fire Orange will grow to a height of 12 to 18 inches.
Coleus Colorblaze® Torchlight™ was an outstanding coleus in a large container in 2021. This vigorous coleus doesn’t fade; its fuchsia, maroon, and green colored foliage stayed true throughout the growing season. Colorblaze® Torchlight™ is easy to grow, very uniform in growth and performs equally well in sun or shade.
Petunia Itsy™ Magenta had exceptional color coverage and excellent vigor in 2021. Each of these unique petunia plants had hundreds of tiny, vibrant magenta-colored flowers that made a big statement with garden visitors! Grew to a height of 4 to 6 inches and each plant had a width of 18 to 24 inches.
Petunia Surfinia® Purple Heart was a fast-growing petunia which produced a prolific number of eye-catching blooms all season-long. Each flower featured a pattern of five unique purple hearts. Offers a vigorous mounding spreading habit with a plant width of about 18 inches but does not spread out of control.
Salvia farinacea Sallyfun™ Sky Blue offers abundant, showy sky-blue flower spikes that rise above the aromatic foliage all season long. Bees and butterflies were attracted to this annual flower. Grow in full sun. With a height of 20 to 24 inches, Sallyfun™ Sky Blue is excellent for use as a garden background. This eye catcher makes for a wonderful cut flower and is deer resistant.
Sunflower Suncredible® Saturn™ The National Garden Bureau designated 2021 as the Year of the Sunflower. Suncredible® Saturn™ is a new everblooming bush variety and a perfect plant for the back of the bed, as an annual screen or along a fence. The blooms are about 4 inches across and don’t need to be deadheaded. Makes for a great cut flower. The most outstanding feature of this sunflower is how long it bloomed late into the growing season in our trial garden.
In addition to the annual flower variety trial, the Horticulture Display Garden has also served as an All-America Selections (AAS) Display Garden since 1990. The AAS award recognizes a flower or vegetable variety proven to have superior performance throughout the North American continent. An AAS Display Garden provides the public an opportunity to view the new AAS winners in an attractive well-maintained setting. Additionally, the Horticulture Display Garden is the only AAS Trial Ground site in Minnesota, where AAS entries are planted next to comparisons and evaluated by an AAS Trial Judge.
All flowers in the Horticulture Display Garden are labeled, allowing visitors to take note of top performing cultivars under regional conditions. The Horticulture Display Garden is open daily from dawn until dusk; admission is free. The Garden is located at 46352 State Hwy 329, Morris, MN.