The Role of Public Gardens

Sarah Leach Smith

Most of you are quite familiar with trial gardens. They play an integral role in the plant introduction and production processes, helping breeders and growers make informed decisions about which plants to release to the commercial market through the collection of plant performance data. However, trial gardens are capable of filling other roles as well—it all just depends on the goals and objectives of the institution.

In addition to breeding companies and commercial growers, universities and public gardens are trial garden stakeholders as well. They’re all key players in the plant evaluation process, from initial plant introduction to homeowner installation, but can play a different role than what you may be
thinking.

A trial gardens thesis
I recently completed the Longwood Graduate Program in Public Horticulture at the University of Delaware, a program that focuses on public garden management. I wanted to identify precisely what role public gardens and arboreta play in the plant introduction process and find ways that they could be even more significant to the industry. Through surveys and interviews with horticulture industry professionals, I was able to get a holistic view of trial gardens and what they mean to the industry, while concentrating specifically on how public gardens fit into everything.

Both survey and interview results highlight challenges in the industry with regards to plant trials. With such different trial garden stakeholders, there are many different institutional goals. Survey results suggested that public gardens want to emphasize visitor education, universities seek to provide teaching opportunities, breeders focus on introducing new plants each year and growers desire to be on the forefront of the new plant introductions so that they may sell them to their clients.

That prompts several questions: Is it possible for everyone to be on the same page? How can each stakeholders learn and benefit from each other? More specifically, what role should public gardens play to have the greatest impact on this process?

An industry shift
A majority of survey participants responded that plant trial programs have increased in size over the last five years, while a majority of the breeding company participants reported that the amount of plant material sent to public gardens has actually decreased. Anne-Marie Hardie wrote in the November 2014 issue of GrowerTalks that external field trials at universities and public gardens were traditionally a crucial step in the plant introduction process, providing unbiased evaluations that informed growers about which new plants they may consider producing in future seasons.Breeding companies are now finding it more economical to send plant material to their grower customers to trial.

“Then, you have the customer seeing it first hand and they are going to know how to grow something from the get-go once they start to buy the product,” All-American Selection Executive Director Diane Blazek explains. By sending plant material directly to growers to trial, breeding companies save both money and time in the plant introduction process.

Not all plant trials are created equal
For the purposes of my research, I distinguished between two types of trial gardens: breeder trials and consumer trials. Breeder trials differ from consumer trials in that they’re focused on providing results for breeders and growers, while the audience of consumer trials is the general public. Breeders and growers aim to reach those who will make a major investment in the product, possibly ordering tens of thousands of units. To the contrary, a public garden’s audience is its visitors, who may be interested in purchasing one or more of a plant that they like. These are two well-defined levels of plant trialing, but I believe that they have a lot to offer each other.

The difference between the types of plants being trialed is also notable. Annuals complete their entire life cycle in one growing season and, therefore, for plant breeders and growers, the shelf life of these plants is extremely short and the timeline for market introduction is very quick. The trialing and production phases for perennials, however, take longer than annuals, and they should last in a home garden for several years. Trees and shrubs take even longer.

Recognizing these differences is critical to understanding how trial garden stakeholders can most effectively utilize their strengths. In speaking with companies and growers with strong annual breeding and growing efforts, like Ball Horticultural and Costa Farms, it becomes clear how the timeline and audience for new annual introductions dictate the processes.

For annuals, companies are constantly working to breed and select the new plant trend for the next season. This pace is rapid, so it’s understandable how trialing directly with a commercial grower would help the process to move as quickly as possible. Additionally, the primary audience for these annual breeding and growing companies are wholesale clients buying in large quantities, such as Walmart and Home Depot. Acknowledging how annual trialing at a public garden could slow down or hinder the introduction process, and the fact that they have entirely different audiences, actually highlights a way in which these institutions could play a major role in perennial and woody plant trialing.

Turning a challenge into an opportunity
While there are still many university and public garden annual trials that are quite successful and well-known, such as Colorado State University and the Dallas Arboretum, the undeniable trend is that breeding companies are sending less annual plant material to these institutions in favor of commercial trials. However, this opens up an opportunity for universities and public gardens to trial perennials and woody plants.

Pictured: An example of how public gardens emphasize visitor education with handy signage.

Since they last longer than one growing season, it’s imperative that perennials be trialed for more than one year. Also, because of the enormous variation among perennial genera, it could take longer than two years to get an accurate assessment of perennial plant performance in the landscape.

For Ball perennials, Jim Nau, Manager of The Gardens at Ball, said that commercial growers receive plant material for trials one year in advance of potential introduction. Accordingly, the grower can observe plant performance over the winter months. However, this strategy may leave many questions unanswered: How will it perform after two or three winters? Will it spread vigorously in the garden over time or will it create a large clump? Will it be short-lived in the garden or could it last for many years? It’s understandable that breeding companies and commercial growers may simply not have the ability to do such long-term trials pre-introduction.

With external and/or internal funding support, universities and public gardens could be perfect to provide such data. These could be both breeder and consumer-focused trials, providing valuable, unbiased, post-introduction feedback about plant performance to breeders and informing homeowners about perennials that fare well in their region over time. Perennial trials like these currently exist, which demonstrate strategies for both external and internal funding sources.

The University of Georgia (UGA) Trial Gardens, which was primarily an annual trial for the hot and humid conditions in Athens, Georgia, has evolved over the years to feature more perennials. Director Dr. John Ruter is planning to include even more perennials in the future. The UGA Trial Gardens are primarily for breeder trials, sending data back to breeding companies regularly. However, due to the popularity of the UGA Gardens and the number of annual visitors, their trials provide regionally specific information about ideal plants for home gardening consumers. Breeding companies provide plant material and John charges them a fee to have their plants trialed there.

Chicago Botanic Garden (CBG) is an example of a public garden with an extensive perennial trial garden that’s primarily funded internally. Consumers benefit most from CBG’s performance data, and a partnership between CBG and Fine Gardening magazine help disseminate trial results to home gardeners nationwide. Both the UGA Trial Gardens and CBG’s trial garden illustrate how a perennial trial could be right at home at a university or public garden.

Fitting it all together
Data collected at university and public garden perennial trials can also be uploaded to the National Plant Trials Database (planttrials.org), which was launched in 2012. The National Plant Trials Database (NPTD) is a central repository for plant trial data from across the country and was inspired by the need for a standard rating scale and trialing method amongst all trial garden institutions. The site requires a login and password and is geared toward industry professionals, specifically breeders and growers, allowing access to trial data to quickly compare how one plant performed at many different locations. Presently, most of the data on the site is for annual and tropical genera, but AAS is actively working to increase the number of perennial genera represented.

Despite the relevancy of the NPTD, the majority (66%) of my survey respondents indicated that they weren’t yet familiar with it. As the site grows and gains popularity among trial garden stakeholders, perhaps AAS will consider adding a consumer aspect to the site and allow the public to learn about perennials that have performed successfully in their region.

Public gardens are in an excellent position to play the role of consumer educator, and post-introduction perennial and woody trial gardens, like the one at Chicago Botanic Garden, seem like a perfect fit. GT

Sarah Leach Smith recently received her MS from the Longwood Graduate Program in Public Horticulture at the University of Delaware. She’s now the Visitor Services Coordinator at Sarah P. Duke Gardens in Durham, North Carolina.