Penn State Flower Trials aid industry, consumers in picking posies

Master Gardeners support 85-year-old tradition

The Penn State Flower Trials — in its 85th year — has a powerful benefit in Pennsylvania and beyond. Penn State's Southeast Agricultural Research and Extension Center in Manheim, Lancaster County, serves as the epicenter of the trials. Credit: Alyssa Collins / Penn StateCreative Commons

UNIVERSITY PARK, Pa. — Each May, the expression "flower power" takes on a new meaning at Penn State's Southeast Agricultural Research and Extension Center in Manheim, Lancaster County, when an 85-year-old tradition — the Penn State Flower Trials — gets underway.

"Penn State's College of Agricultural Sciences runs one of the oldest and largest flower trials in the world," said Sinclair Adam, who directs the program, with guidance from a 42-member floricultural advisory board. "It is an amazing slice of floriculture that has a powerful benefit in Pennsylvania and beyond."

According to U.S. Department of Agriculture statistics, the estimated annual wholesale value of Pennsylvania's floricultural products is $193 million, making the state one of the top 15 producers in the nation. The trials provide floricultural companies with valuable information on flower varieties that perform well — or not so well — in various environments around the state, so that those companies can grow and market the most favorable ones.

"Everyone benefits because healthy flowers encourage a diverse and healthy ecosystem, support the economy, and add aesthetic value to our communities," Adam said. "Plus, the trials help homeowners and hobbyists answer questions such as 'what kind of petunia should I grow?'"

The southeast site serves as the epicenter of the trials, where Alyssa Collins, director of the center — whose expertise is plant pathology — oversees the intake and preparation of about 15,000 seedlings, which represent about 900 varieties. These submissions are received from 30 floriculture companies in the United States and Europe.

"We have a rich variety, from angelonias to zinnias and everything in-between," Collins said.

In addition to the Manheim location, samples are evaluated at collaborative sites at Hershey Gardens in Dauphin County; North Park in Allegheny County; the Russell E. Larson Agricultural Research Center at Rock Springs in Centre County; and new this year, The Arboretum at Penn State in Centre County.

Having flowers at various locations provides a comprehensive look at how well they hold up regionally, Adam explained. "A variety of aster that flourishes in Lancaster County might falter in Pittsburgh. Climates and conditions vary throughout the state." 

Over the summer, flowers are evaluated by Penn State horticulture experts and rated on a scale from one to five on factors such as flower quality; overall growth and uniformity based on moisture, heat, soil fertility and other environmental conditions; and length of life. Each rating represents an investment of about 30 hours. In early September, the results are tallied and shared online at

An undertaking of this magnitude requires a horde of helpers, and Adam and Collins said they are fortunate to have support from Penn State staff at the sites as well as from Penn State Extension Master Gardeners, a trained volunteer troop that supports sustainable horticulture and environmental stewardship across the state.

The Master Gardeners program currently boasts 2,774 active and 391 newly trained volunteers, who provided more than 200,000 volunteer hours in their communities last year. More than 3,700 of those hours — and 130 volunteers — were devoted to the flower trial program.

"We simply could not do what we do without the Master Gardeners," Adam said.

Collins concurred and shared an example of how they do most of the heavy lifting. "We have thousands of plants arrive at the same time, and all have to be planted within a few days. The Master Gardeners step up every year to make sure it happens and then help throughout the season at all locations, with tasks that aren't fun, such as weeding, pruning and fertilizing, but they do it for the love of the program and flowers."

Anne Hawk, a Master Gardener coordinator and program assistant, who has been with the program since 1992, said the group's support of the project is a labor of love. "Master Gardeners all share a passion for improving the environment, and the flower trial program allows us to use our talents to foster horticulture interests in the state and beyond. I believe that our volunteers' allegiance to the program is among the reasons for its success."

Adam and Collins noted that, in addition to the Master Gardeners, they are fortunate to have salespeople, growers, flower breeders and other floriculture professionals work side-by-side with them to plant, protect and promote the trials. "They all know how important it is, because when these plants succeed, the whole industry will succeed," Collins pointed out.

Flower trial sites are open to the public. In fact, Collins noted that the combined locations of the Penn State Flower Trials attract more than 250,000 visitors annually. The hub in Manheim is open every day from dawn until dusk in June, July and August.

"It makes for a nice day trip," she said. "We have a lot of people who stop on their way to or from the shore. Everyone is excited to see one of the largest flower trials in the country."

More information about the trials is available online at To learn more about the Master Gardener program, visit

Dauphin County Master Gardeners Jerry Yocum and Carol Brightbill organize trays of trial plants at Penn State's Southeast Agricultural Research and Extension Center in Manheim, Lancaster County. Credit: Alyssa Collins / Penn StateCreative Commons

Last Updated May 07, 2018