A new plant! Thousands are tested, hundreds are introduced, dozens are selected as the most promising new plants on the market. And each year, customers flock to garden centers, magazine pages or smartphones in hand, demanding the newest of the new.

Trials continue even after plants have been on the market for a while, often for suitability in different hardiness zones and regions.

Awards vs. trials

Various entities, ranging from private breeders through botanic gardens and arboreta to universities and their extension services, issue annual plant awards. While these honors may, indeed, be based on scientific trials and evaluations, they also can be determined by popular vote. Whether voters are home gardeners and garden center customers or plant professionals and hort society members, their endorsement of a plant signifies an elevated value. The label “XYZ Award Winner” or “Top 10 in XYZ Plant Trials” can add dollars to the retail price and earn a special kind of “brand” loyalty.

California Spring Trials (formerly known as the “Pack Trials”) each year invites industry professionals to take part in a week-long, self-directed tour of various locations throughout the state. In addition to showcasing new plant varieties, this is the event during which merchandising programs and concepts also are introduced.

Evaluation programs, such as those operated by the Chicago Botanic Garden and Mt. Cuba Center, devote years to studying select species and then producing comprehensive reports on the results. The Heuchera Research Report from Mt. Cuba Center was released in December. It is the result of a two-year-long study conducted by the center’s research staff, which evaluated 83 Heuchera cultivars for vigor, fullness and uniformity over the course of three seasons. The top 10 selections— those that show the most promise of flourishing in the mid-Atlantic region— are named in the report, which can be downloaded here: http://www.mtcubacenter.org/horticultural-research/trial-garden-research.

At the Chicago Botanic Garden, horticulturist Richard Hawke heads up the organization’s Plant Evaluation program, which last year alone tested more than 1,200 taxa (about 55,000 plants). Evaluation studies at the Garden are conducted for four years for perennials; six years for shrubs and vines; and seven to 10 years for trees. To date, nearly 40 Plant Evaluation Notes have been produced as the result Hawke’s studies.

A Colorado case study

Colorado State University’s Flower Trial Garden in Fort Collins is the site each year of evaluations of annuals, perennials and “cool season” plants—those that have the potential to survive the region’s tough winters. A Perennial Trial Committee evaluates hundreds of plants and narrows the offerings to a list of “Top Perfomers” and a few that are considered “Too Good to Wait”—meaning that the plants have not yet completed the entire two-year trial period, but show exceptional promise.

This year, judges determined the five “Top Performers” to be:

Agastache × hybrida ‘Blue Boa’

Blue Boa agastache (Agastache × hybrida ‘Blue Boa’; PP24050) from Terra Nova Nurseries. “Non-stop flower power resulted in a season long splash of bright lavender-blue color that covered the plant in blooms from top to bottom. Excellent vigor and a relatively large growth habit would make this a good choice for the back of a perennial border that needs color. Besides all the beauty, this plant is also recommended for its drought tolerance and ability to attract bees and butterflies.”

Echinacea spp. ‘Lelani’

Leilani coneflower (Echinacea spp. ‘Lelani’; PP23526) from Terra Nova Nurseries. “Tall, vigorous plants ‘wowed!’ visitors with the prolific display of ‘warm, buttery yellow’ flowers. Blooming occurred over a long period and the plants maintained superior controlled vigor for good uniformity and overall appearance.”

Echinacea purpurea ‘Profusion’

Profusion coneflower (Echinacea purpurea ‘Profusion’) from Eason Horticultural Resources.

“Flowers had a unique appearance and overall shape due to many petals with a nice shape and a large, dark center. The dark stems also complemented the flower petals and dark center. Plants were compact but flowering was very profuse and lived up to its name. The light lavender petals also faded nicely into an ‘antique’ lavender color that was also very attractive and extended the bloom time.”

Heuchera × hybrida ‘Georgia Plum’

Georgia Plum coral bells (Heuchera × hybrida ‘Georgia Plum’; PP24507) from Terra Nova Nurseries. “Plum colored foliage was impressive all season and did not show any signs of fading. Besides the plum color, foliage also had a nice silver sheen for good color impact throughout the growing season. Plants were very uniform and had excellent growth habit. Predominantly grown for the foliage, the light pink/plum flowers were few but still attractive.”

Hibiscus × hybrida ‘Midnight Marvel’

Midnight Marvel hibiscus (Hibiscus × hybrida ‘Midnight Marvel’; PP24079) from Walters Gardens/ Proven Winners®. “The flowers and foliage made a spectacular combination. Dark bronze foliage made a perfect backdrop to the beautiful flowers with a rich, red color. Many flowers came into bloom together and created a good visual impact. Plants were vigorous but maintained a nice size without getting too large as observed in some other Hibiscus.”

Those plants designated “Too Good to Wait” are:

Coreopsis verticillata ‘Electric Avenue’

Electric Avenue coreopsis (Coreopsis verticillata ‘Mayo Clinic Flower of Hope’ PPAF or ‘Electric Avenue’) from Creek Hill/ Eason. “Bright yellow flowers were very showy and flowering was solid all season. Plants were vigorous, uniform and maintained good stature from spring to fall. Fine textured foliage and a nice flower shape contributed to a very pleasing overall affect. This is good plant for attracting bees. Overwintering survival was impressive with no losses despite a difficult winter in Fort Collins, Colorado, during 2013-2014.”

Festuca glauca ‘Casca11’ (‘Beyond Blue’)

Beyond Blue fescue (Festuca glauca ‘Casca11’; PP #23307 ) from Skagit Gardens. “This fescue is considered to have the best ‘blue’ color out there! Plants are larger than F. ‘Boulder Blue’ but maintain a nice ‘ball’ shape and do not open in the middle. Flower stems fade and disappear amongst the foliage for a superior appearance. This is an improved variety over older ones for foliage color.”

Sunrosa™ Red rose (Rosa × hybrid Sunrosa™ Red) from Suntory® Flowers. “Constant red flowers and impressive growth habit make this plant attractive all season. Glossy dark green foliage had no signs of chlorosis or disease. Red flowers did not fade and bloomed steadily from mid-June through October. Small foliage and a dwarf compact growth habit make this a good choice for the smaller or midsize landscapes. The compact growth habit is maintained without any pruning.”

Trials and awards across the country

We’ve listed here just a few of the plant trial and evaluation programs across the country, each of which tests plants under specific criteria designed to identify the “best” plants for a particular geographic region or for overall reliability and performance in the home garden.

Many plant-specific organizations host trials and awards, such as the American Hemerocallis Society (http://www.daylilies.org), the American Hosta Society (http://www.hosta.org) and the American Rhododendron Society (http://www.rhododendron.org), among others.

Tried-and-true, these plant evaluation programs can help you determine your optimal choices among the ever- growing list of “new,” “improved” and “best” plants available.