Featured Five 2025: Favorites from Four Star Greenhouses Display Gardens

Caitlin Splawski<splawski@msu.edu> and Heidi Lindberg<wollaege@msu.edu>, Michigan State University Extension - August 26, 2025

Are you seeking proven performers for the season ahead? Check out Part 2 of our series highlighting top picks from the 2025 Michigan Garden Plant Tour trial sites.

A scenic garden landscape featuring a rustic wooden gazebo surrounded by colorful flower beds. The beds are filled with pink, purple, yellow, and red flowers, with manicured shrubs and trees in the background under a partly cloudy sky. — Photo by Caitlin Splawski, MSU Extension.

Every year, Michigan State University and Michigan’s leading young plant producers host a free open house at their trial sites and display gardens for growers, landscapers and retail operators to learn about a wide range of ornamental crops. Industry professionals can see for themselves which new varieties perform the best under various conditions, including in the ground and in containers. The tour lasts for two weeks and was held this year from July 28-Aug. 8, 2025.

This year, there were seven trial gardens at different locations throughout central lower Michigan: DGI Propagators, Four Star Greenhouses, Mast Young Plants, Michigan State University (MSU) Trial Garden, Pell Greenhouses, Raker-Roberta’s Young Plants and Walter’s Gardens.

If you couldn’t make it out to every trial site, you’re in luck! Heidi Lindberg and Caitlin Splawski, Michigan State University Extension educators, traveled to each site, picking favorites and snapping photos along the way. We’ll cover our favorites from each trial site in this article series.

Part 1 of this series covered Michigan State University Extension’s top picks from the trial garden at DGI Propagators. Part 2 will feature the favorites from Four Star Greenhouses.

Featured Five at Four Star Greenhouses

Per usual, Four Star Greenhouses’ display gardens do not disappoint. Though they do not take up a large footprint, they are jam-packed with amazing annual color. Their display starts by taking you through their new arrivals for 2026 displayed in both aquapot containers and hanging baskets. You’re able to get a full picture of what these new plants have to offer in containers by themselves as well as in combination with other suggested varieties. You then move into display areas that feature new varieties within in-ground display beds. Continuing through the garden, you’ll also encounter Proven Winners top-sellers as well as previous years’ award winners. Several new varieties for 2026 stood out:

Ipomea Sweet Caroline ‘Medusa Black’ – Proven Winners
Lobularia ‘White Knight’ – Proven Winners
Didelta ‘Silver River’ – Proven Winners
Petunia Supertunia Vista ‘Cool Jazz’ – Proven Winners
Cleome ‘Señorita Rosalita’– Proven Winners

Ipomea Sweet Caroline ‘Medusa Black’

Add texture and heat tolerance to your lineup with this new take on a garden classic. Sweet potato vine has long been a favorite of gardeners for adding color and form to containers. With a mounding/trailing habit and distinctly palmate leaves (Photo 1), Sweet Caroline Medusa Black is a great addition to containers, hanging baskets (Photo 2) or annual beds in either sun or shade (Photos 3-4).

Two images of ornamental sweet potato vine. Left: Close-up of deeply lobed purple foliage with hints of chartreuse green new growth. Right: A large hanging basket on a pergola, filled with trailing purple foliage mixed with magenta and white flowers. — Photos 1 and 2. The deeply lobed, palmate leaves of Sweet Caroline Medusa Black create texture in the garden. Shown here in a hanging basket combination with Supertunia Vista ‘Silverberry’ and Superbena Royale ‘Plum Wine.’ Photo by Caitlin Splawski, MSU Extension.

Two garden bed views. Left: A mix of deep purple foliage, bright pink begonias, and bold green elephant ear plants in a landscaped bed. Right: A sweeping garden border layered with purple salvia, pink petunias, orange-yellow flowers, and dark-leaved groundcover. — Photos 3 and 4. Sweet Caroline Medusa Black growing in shade (left) and full sun (right). Photo by Caitlin Splawski, MSU Extension.

Lobularia ‘White Knight’

This year, we’re choosing to feature another unsung hero when it comes to annual combinations and garden borders. We all know Lobularia, sweet alyssum, for its early spring performance and icy-cool white to pink and purple color variations. The variety White Knight stood out to us because of its performance in hot weather and its tidy habit. The White Knight features larger clusters of tidy white blossoms that densely cover the foliage, even in August (Photos 5-6). A perfect addition for gardeners looking to entice pollinators to their garden borders (Photo 7).

Two views of white alyssum. Left: A rounded blue pot spilling over with dense clusters of tiny white flowers. Right: A close-up of the small blooms with green foliage, showing their delicate texture. — Photos 5 and 6. Lobularia White Knight showcasing a neat habit with loads of blooms in containers. Photo by Caitlin Splawski, MSU Extension.

A garden path lined with colorful flower beds. Foreground features a patch of white alyssum, with lavender alliums to the left and bright yellow sunflowers to the right, leading toward a greenhouse. — Photo 7. Lobularia White Knight showcasing a neat habit with loads of blooms as part of a garden border. Photo by Caitlin Splawski, MSU Extension.

Didelta ‘Silver River’

In keeping with the theme of heat tolerance, Didelta ‘Silver River’ is another new variety to feature (Photo 8). For those looking to shake things up and try something different than Dichondra ‘Silver Falls,’ Silver River offers great accent potential with its silvery, semi-succulent foliage. With slightly less vigor than Dichondra, Silver River is a good choice for mixing into containers with other drought-tolerant plants and is adapted to hot, dry conditions.

A large decorative pot filled with dense silver-gray foliage. The plant has fine, narrow, almost succulent-like leaves, forming a rounded mound. A wooden bench and other containers are visible in the background. — Photo 8. Didelta Silver River showing its mounding and trailing habit in this container planting. Photo by Caitlin Splawski, MSU Extension.

Petunia Supertunia Vista ‘Cool Jazz’

Supertunia Vista is Proven Winners’ most vigorous petunia series, so if you are looking for landscape performance with large spreading mounds of color, this is the series for you. With nearly every colorway in this series already touted as a best-seller, Cool Jazz adds an icy purplish-pink hue to the series lineup that offers early season performance plus long-lasting heat-tolerance (Photos 9-10).

Two displays of petunias. Left: A hanging basket overflowing with bright pink and light lavender petunias under a pergola. Right: A garden bed layered with pale purple petunias, dark purple annuals, and coleus, set in front of large greenhouses. — Photos 9 and 10. Petunia Supertunia Vista Cool Jazz pictured left in a hanging basket along with Supertunia Vista ‘Jazzberry.’ On right, Vista Cool Jazz in a landscape planting with Angelonia Angleface ‘Blue,’ Coleus ColorBlaze ‘Torchlight’ and Cyperus Graceful Grasses ‘Prince Tut.’ Photo by Caitlin Splawski, MSU Extension.

Cleome ‘Señorita Rosalita’

Finally, this last pick is not technically new for 2026, but Cleome Señorita Rosalita couldn’t help but be noticed in this year’s display gardens. This plant boasts being a top-seller for good reason and has earned the title of “Landscape Annual of the Year” for 2026. With clean, dark green foliage and numerous clusters of lavender-pink flowers, you can count on Señorita Rosalita to bloom all season long (Photos 11-12).

Two beds of mixed flowers. Left: Yellow lantana and white daisies bloom at the base of tall purple cleome flowers. Right: A curved flower border featuring purple cleome, lavender salvia, dusty miller foliage, and low pink annuals, with sweeping flower beds in the background. — Photos 11 and 12. Two ways to feature Cleome Señorita Rosalita. Pictured left with Lantana Luscious Royale ‘Lemon Tart,’ Bidens ‘Campfire Marshmallow’ and the new Lobelia ‘Laguna Royale Pink.’ Pictured right with Salvia ‘Rockin’ Deep Purple,’ 2026 annual of the year Jamesbrittenia ‘Safari Dusk,’ 2026 petunia of the year Supertunia Hoopla ‘Vivid Orchid’ and Helichrysum ‘White Licorice.’ Photo by Caitlin Splawski, MSU Extension.

Other notable varieties

Some other notable varieties shown at Four Star Greenhouses display gardens during this year’s tour included the Petunia Supertunia ‘Bordeaux Improved,’ which shows much improved bloom performance over ‘Bordeaux’ (Photos 13-14). Lobelia ‘Laguna Royale Azure’ (Photo 15), Calibrachoa Superbells ‘Magic Double Grapefruit’ (Photo 16) and Begonia Surefire ‘Cascade Red’ (Photo 17) were noteworthy as well.

Two displays of Supertunia Bordeaux petunias. Left: A blue ceramic pot dripping with purple-and-white veined petunias, labeled “Supertunia Bordeaux Improved.” Right: A rustic gray planter with slightly larger purple-veined petunias, labeled “Supertunia Bordeaux.” — Photos 13 and 14. Petunia Supertunia Bordeaux Improved (left) compared to Petunia Supertunia Bordeaux (right). Photo by Caitlin Splawski, MSU Extension.

Three photos of garden plants. Left: A large stone planter filled with masses of small purple-blue flowers. Center: A colorful cluster of yellow, pink, and peach bicolor flowers with a “Top Pick 2026” sign. Right: A bright blue ceramic pot overflowing with glossy-leaved red begonias under a pergola walkway. — Photos 15, 16 and 17. Lobelia Laguna Royale Azure (left), Calibrachoa Superbells Magic Double Grapefruit (center) and Begonia Surefire Cascade Red (right). Photo by Caitlin Splawski, MSU Extension.

This article was published by Michigan State University Extension. For more information, visit https://extension.msu.edu. To have a digest of information delivered straight to your email inbox, visit https://extension.msu.edu/newsletters. To contact an expert in your area, visit https://extension.msu.edu/experts, or call 888-MSUE4MI (888-678-3464).

MSU Extension Floriculture & Greenhouse Crop Production