Still in bloom: Penn State Flower Trials mark 90 years

UNIVERSITY PARK, Pa. — For 90 years, the Penn State Flower Trials have helped growers answer a simple question: Which flowers are best worth planting? This summer, the trials are celebrating that legacy by pairing cutting-edge new varieties with “Oldies but Goodies,” classic flowers that have stood the test of time.

“Sometimes your grandmother’s favorite petunia really is still the best,” said Alyssa Collins, director of Penn State’s Southeast Agricultural Research and Extension Center in Manheim, Pennsylvania, where the trials take place.

Operated by Penn State’s College of Agricultural Sciences, the trials are among the oldest and largest flower trials programs in the world. Nearly 1,000 annual and perennial varieties from about 30 floriculture companies are planted and evaluated each year under Pennsylvania growing conditions.

“The flower trials have several purposes,” said Krystal Snyder, horticulture extension educator and interim director of the Penn State Flower Trials. “The big one is that breeders from all over the world trial their plants here to see what performs well in our location.”

The trials play an important role in the Mid-Atlantic and Northeast, where relatively few flower varieties are bred and tested because of the region’s humid summers and unpredictable weather conditions, noted Collins, whose expertise is in plant pathology. She noted that the center's location makes it easily accessible to visitors from across Pennsylvania and much of the eastern United States.

“If a plant can do well here in our conditions," Collins said, "it’s likely going to do well for the majority of buyers in the region, and these folks can come out and see it for themselves.”

The trials also provide a resource for greenhouse growers, garden centers and landscapers evaluating new varieties before deciding what to stock and sell.

“Being in Lancaster County, with nearly 300 licensed greenhouse growers, makes the trials especially accessible to the industry,” Snyder said.

The gardens are open and free to the public throughout the summer. Visitors can stroll through rows of colorful blooms, compare varieties side by side and gather ideas for their own gardens.

“Visitors should plan to take pictures or notes so that they can go to their local independent garden center and ask for their favorite varieties to be carried,” Collins said. “Growers and garden centers place their orders for the following year in September and October, so that’s the time to encourage them to order a variety that catches their fancy.”

This year also marks the launch of Penn State’s first fall flower trials, featuring plants selected for late-season color and performance. The showcase will include mums, ornamental peppers, marigolds, celosia, pansies and other “late bloomers.”

Sarah Mitchell, who recently joined Penn State as flower trials manager, said the program’s reputation was one of the factors that drew her to the position. Before joining the University, she worked in sales, greenhouse management and technical service for commercial growers.

“I’ve used the Penn State Flower Trials to my advantage,” Mitchell said. “When I bring people here or reference variety evaluations, I build credibility as a horticultural professional.”

Snyder evaluates the plants three times throughout the season, rating them on factors such as foliage, flower quality, and overall growth and uniformity.

“For annuals, we’re looking for plants that flower all season long,” Snyder said, adding that the ratings are published online almost immediately. “If I rate plants Monday morning, the results are online by Tuesday morning.”

The flower trials rely heavily on Penn State Extension Master Gardeners, who assist with everything from planting and weeding to organizing and maintaining the gardens throughout the season.

“There are Master Gardeners still volunteering with the trials today who were here when the first flowers were planted in the ground at the center in the 1990s,” Collins said. “They care very deeply about the legacy of this program and ensuring the success and longevity of it.”

Snyder noted that the Master Gardeners’ institutional knowledge and eagerness to help are crucial.

“We could not do this work without them,” she said.

The program supports research as well. One project involves FloraCount, an app developed by researchers in Penn State’s Center for Pollinator Research to measure how attractive specific flower varieties are to pollinators such as bees and butterflies.

Collins said the app provides gardeners and growers with a science-based way to evaluate pollinator-friendly plants, rather than relying on broad marketing claims. Researchers have used the flower trials to test and refine the app on new cultivars over the past five years with help from interns and Master Gardeners.

The gardens also provide insight into changing consumer preferences. Snyder said growers and consumers increasingly are looking for low-maintenance plants with qualities such as longevity and drought tolerance.

Snyder noted that the trials support an important part of Pennsylvania’s agricultural economy. Annuals and potted perennials represent a more than $200 million industry in the state, she said.

The program’s longevity reflects decades of support from greenhouse growers, breeding companies and industry partners, many of whom continue to volunteer and advise the trials through the Pennsylvania Floriculture Advisory Board.

About 3,000 to 4,000 people visit the trials each year through events, tours and walk-in visits. The trial gardens are open to visitors, free of charge, from June 1 through Aug. 31, sunrise to sunset.

In addition to self-guided visits, Penn State Extension will host a series of free summer open houses featuring seasonal highlights and guided tours of the center’s demonstration gardens. More information is available on the Penn State Extension website.

Horticulture professionals can network with industry colleagues and explore the latest flower varieties at the annual Flower Trials Field Day, scheduled for 9 a.m. to 3:30 p.m. July 23 at the center. The event is designed for greenhouse growers, nursery and landscape professionals, retail greenhouse operators, greenhouse industry brokers and sales personnel, allied trades personnel, botanic garden personnel, and extension and university staff.

New this year, attendees can participate in guided tours offering additional insights into the trial selections and their performance. More information is available on the Penn State Extension website.

Visitors can explore the nearby Master Gardener Idea Gardens, Native Garden, Butterfly Garden, Vegetable Garden and other demonstration gardens located throughout the center.

“The Flower Trials are truly a gem at the center because of our location and the objective work we do,” Mitchell said. “When anyone arrives here between June and September, masses of colorful flowers greet them. The Flower Trials set a positive, energetic tone from the get-go.”