Highlights from 2025 Field Trials: University of Tennessee Gardens
(Information provided by Jennifer Northam, Collections Manager & Horticulturist)
View all
The University of Tennessee Gardens saw a 2025 season that brought the usual stretches of hot, humid weather, but overall felt less brutal than the previous summer. Rainfall totals were lower, but showers arrived roughly every other week, which meant that after initial establishment, supplemental overhead irrigation was rarely needed.
This year, UT trialed 135 varieties grown from seed and plugs in the greenhouses, with plants ready for ground planting in May. Volunteers and student interns helped push everything into the beds so evaluations could begin in June.
Three new full-sun perennial beds and one new shade perennial bed were installed. The added space allows UT to more easily accept growing perennial trials, and since perennial trials take up real estate for several years, the expansion was an excellent addition to the perennial trial program.
Weed control remains one of the most persistent challenges. Consistent hand-pulling before weeds can reseed is essential, and increasing mulch applications has also been helpful. The gardens rely on wood-chip mulch sourced from trees that have fallen or been removed around campus, helping keep beds covered and competition down.
Top Performers and Standout Varieties for 2025 at the University of Tennessee Gardens
The following varieties stood out in the 2025 trials for vigor, color, and overall garden performance:
Begonia Begonia hybrid Surefire Cascade™ Red (Proven Winners)
Begonia Begonia hybrid Surefire Cascade™ Red (Proven Winners)
A bold, beautiful red begonia with a unique arching shape that held through the summer and remained stunning into fall.
Evening primrose Oenothera hybrid Superlophus™ Sunglow (Proven Winners)
Evening primrose Oenothera hybrid Superlophus™ Sunglow (Proven Winners)
Bright yellow flowers covered compact, spreading plants that handled heat and humidity with very little attention.
Petunia Petunia hybrid Supertunia Vista® Cool Jazz™ (Proven Winners)
Petunia Petunia hybrid Supertunia Vista® Cool Jazz™ (Proven Winners)
Produced a mass of light lavender-pink blooms with strong vigor and reliable performance through summer heat.
Begonia Begonia hybrid Surefire® Rose (Proven Winners)
Begonia Begonia hybrid Surefire® Rose (Proven Winners)
Like the rest of the Surefire® series, this begonia performed through summer and really shined into fall. ‘Surefire Rose’ offered excellent color and strong contrast in mixed plantings.
Coleus Coleus scutellarioides ColorBlaze® Wicked Witch™ (Proven Winners)
Coleus Coleus scutellarioides ColorBlaze® Wicked Witch™ (Proven Winners)
Noted for its impressive vigor and ability to fill space with both height and width. It held up to heat and humidity and works well as a medium-height annual to tier between lower borders and taller backdrops.
Lantana Lantana camara Luscious® Basket Tangeglow™ (Proven Winners)
Lantana Lantana camara Luscious® Basket Tangeglow™ (Proven Winners)
A hardy lantana with medium vigor, a great, balanced shape, and multi-level blooms across the plant. The bright orange-and-yellow bi-color flowers created a cheerful glow in the garden.
Petunia Petunia hybrid Supertunia® Bubblegum® (Proven Winners)
Petunia Petunia hybrid Supertunia® Bubblegum® (Proven Winners)
A flower-power workhorse, forming a vigorous sea of hot pink that held its color until truly cold weather arrived.
Sweet potato vine Ipomoea batatas Sweet Caroline Medusa™ Green (Proven Winners)
Sweet potato vine Ipomoea batatas Sweet Caroline Medusa™ Green (Proven Winners)
Showed off attractive dentate leaves on a vigorous spreading habit. The foliage contrasts nicely with darker colors and builds a robust mound of texture and color.
Celosia Celosia argentea Sol™ Gekko Green (Fleuroselect Winner)
Celosia Celosia argentea Sol™ Gekko Green (Fleuroselect Winner)
Eye-catching hot pink blooms paired with multicolored foliage made this celosia stand out. Plants formed compact mounds and looked strong all summer.
Lantana Lantana camara Heartland® White (Dümmen Orange)
Lantana Lantana camara Heartland® White (Dümmen Orange)
The most vigorous of the Heartland® series in the trials, blooming all summer and drawing in pollinators. It performed especially well alongside Heartland® Sunrise.
Sunflower Helianthus annuus Desire Red (Fleuroselect Winner)
Sunflower Helianthus annuus Desire Red (Fleuroselect Winner)
An easy-to-grow sunflower with a notably long bloom time and a strong bee following. Dark flowers and foliage contrasted well with yellow sunflowers, making it a striking choice in mass plantings.
Agastache Agastache hybrid Pink Pearl (Terra Nova Nurseries)
Agastache Agastache hybrid Pink Pearl (Terra Nova Nurseries)
This perennial handled summer heat very well and looked strong into fall. Multiple light pink flower spikes covered a compact plant.
For more 2025 field trials information and variety highlights, click here.
Subscribe to eNewsletter
