Esther Jordan, Horticulture Director and Communications Specialist; Steve Poppe, independent annual flower judge; Elsa Eaves, horticulture intern
Research on annual flowers at the University of Minnesota West Central Research and Outreach Center (WCROC), Morris, takes place over four acres in an impressive public display garden. Plant breeding companies from around the world send their annual flower seeds, vegetative cuttings, and unrooted cuttings to the WCROC to be part of our prestigious annual flower trial. Seeds begin to arrive in January, while unrooted cuttings and vegetative plugs start to arrive in March, all with the goal of having healthy transplants by the end of May in time for Minnesota’s growing season.
Annuals are grown in hanging baskets, containers, or planted into landscaped beds within the Horticulture Display Garden. All annual flowers are on display for public viewing from early June into September. Visitors can take note of their favorite cultivars and see how plants respond to regional weather conditions. We are seeing a growing trend in the number of annual flowers that are bred for containers, which is likely due to the rise in consumer demand for container annuals. Companies are expanding into combination planters, such as celosia with begonia (see one of our Top Ten for an impressive example!)
The 2023 growing season for west central Minnesota was drier and much warmer than usual, which created a stressful start for annual bedding plants. The average temperatures for June and July were several degrees higher than historically average, and precipitation was several inches less. Despite regular irrigation, plants exhibited stress by having longer establishment times after planting, slower growth rates, and less flowering while these conditions persisted.
As part of the annual flower trialing process, plants are evaluated several times during the growing season 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. Only the highest rating cultivars earn the distinction as a Top Ten Performing Annual.
Plant breeding companies rely on the valuable feedback from our annual flower trial to market and improve their cultivars. Evaluations from the WCROC annual flower trial are shared with participating plant breeding companies; they may in turn make plant improvements to their cultivars and enter the flower back into trial for another season. Our annual flower report is also made available to commercial nursery producers, floriculture professionals, grower associations, U of MN Extension, and U of MN Master Gardeners to provide cultivar recommendations for Minnesota.
The 2023 Top Ten Performing Annuals
Begonia BIG® Deep Pink Green Leaf
A large, waxy type begonia with very sturdy stems that support an upright and strong branching habit. Its large bright pink and abundant blooms were a knock-out all season long throughout varying temperatures. Flowers were held above the striking green foliage and grew in a very uniform and compact habit. Performed best in a container located in a shady location.
Begonia Viking® Explorer Rose on Green & Celosia Flamma Rose (combination)
This unique combination planting of celosia with begonia made for a stunning display! The celosia provided height in the center of the container, while the begonia filled out beautifully around the edges. Flamma Rose offers an eye-catching bright color that doesn’t fade. Viking® Explorer Rose on Green, a 2022 AAS Ornamental Winner, boasted rose-colored flowers that stood out against the glossy green foliage. Together, they had outstanding garden performance in a large container this season.
Calibrachoa Bumble Bee™ Hot Pink
Bumble Bee™ Hot Pink has an attractive bright yellow eye surrounded by hot pink. This semi-trailing Calibrachoa had excellent garden performance and grew evenly and uniformly in a large hanging basket.
Coleus Talavera™ Pink Tricolor
This stunning shade plant has a lime green edge with a bright raspberry and maroon center. It thrived in our garden bed and grew extremely uniform in a semi-shaded area. Looks fabulous on its own or in combination with other shade plants. Talavera™ Pink Tricolor adds a dramatic touch and would do well in large pots or in the garden landscape. Grows to 20-36 inches.
Petunia Itsy™ Pink
Itsy™ Pink really shined in our 2023 trial as a petite petunia. With exceptional uniform growth and dainty light pink flowers that covered the foliage, it spreads 18-24 inches creating a beautiful blanket in the landscape bed.
Petunia Supertunia Mini Vista® Hot Pink
This spreading type of petunia provides an endless supply of blooms all season long despite changes in weather conditions. The bright pink color stands out nicely against the foliage and attracts a lot of attention. This plant spreads evenly up to 24 inches wide and stays filled in all season without losing foliage at the plant’s center. Makes for a great border plant. Performed best in the ground in full sun.
Salvia Plum Crazy
Pollinators go crazy over Salvia Plum Crazy! Hummingbirds, bees, and butterflies were frequent visitors to this annual all season long. Its deep purple flowers make for a striking contrast to the healthy green foliage. With a height of 36 inches or more, it’s excellent for use as a garden background.
Snapdragon DoubleShot™ Crimson Red
A high-performing snapdragon in July and August? Yes! The DoubleShot Crimson Red delivers. Its open-faced flowers are held up on strong tall stems and produce an abundance of deep red color all season long. Plants grow 18-20 inches tall and do well in sunny locations.
Sunflower Desert Sun
A real knock-out in our Garden this year was the Sunflower Desert Sun. Standing nearly 6 feet tall, its unique flower head presented a burnt orange center with a bright yellow ring around it. With minimal staking, this sunflower held its own under the weather conditions of west central Minnesota.
Zinnia Zydeco™ White
This zinnia exhibits true clean white color. Not only that, but also great disease resistance which leads to the clean appearance of both the foliage and flowers. The large white flowers stand above the foliage. With a branching habit, this plant has uniform growth that appears compact despite its size of 18 inches wide and 12 inches tall. It performed best in full sun in the ground.
Staff Favorite
With nearly 350 flowers on trial, there are bound to be a few varieties that catch our eye even though they didn’t quite make the cut as a Top Ten. Despite having a slow start, Lophospermum Lofos Compact Rose wowed our horticulture staff late in the season with its beautiful flowing foliage and bright flowers, making it an eye-catching display in a hanging basket.
Even though the annual flowers are under evaluation, the plants are placed into an aesthetically pleasing design, allowing visitors to enjoy the beauty of the Garden. The Horticulture Display Garden has been 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.
The Horticulture Display Garden is open daily from dawn until dusk; admission is free. Voted as the “Best Public Display Garden in Minnesota” by WCCO, the Horticulture Display Garden is truly a gem in the Upper Midwest.
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.