Penn State Trial Gardens

Most gardeners put in some annuals every year. Many of us use them in borders, either by themselves or in combination with perennials, to lengthen the flowering season and to add all season color to perennial borders. They go into baskets, large pots and window boxes. Most of the time we buy what is on offer at the local greenhouse or garden center and hope for the best. Will that geranium that is such a great color continue to bloom throughout the season or will it dwindle to one flower every couple of weeks? Does the Million Bells (Calibrachoa) we’ve chosen grow millionbellsuniformly or will it grow out one side of your basket leaving the other side bare? The catalogues aren’t going to give you this kind of information, nor will you find it on the labels of the plants you buy. Books are hopeless, as the newest plants are never going to make it into them. Most of the information that you get from the intenet comes straight from the grower who isn’t going to disparage the plant he is growing. There are independent plant trials and evaluations such as the Perennial Plant of the Year award and the AAS (All American Selection) trials. The former is limited to perennials and chooses one plant and the latter, while reporting on a larger selection of plants, tests them in climates that are as diverse as the Devon Botanical Garden in Devon Canada and Disneyworld gardens in Lake Buena Vista, Florida .( There is also one at Longwood Gardens and one in Schenley Park in Pittsburgh; also one at South Park in Pittsburgh) What a grower needs is an assessment of plants that are grown close to his area and in similar growing conditions. Not all plants thrive everywhere. As Jaci Bruschi from the Schenley Park test garden told the Pittsburgh Post-Gazette, “Not every AAS winner has thrived here. Twinny Peach’ snapdragon started off with a bang but was overtaken by other plants in the bed.” “I just don’t think it was happy here,” she says.

We do have a local or at least semi-local source of information on how new annuals might adapt to our area. Penn State has trial gardens in Manheim, PA where they grow and evaluate new and some older annuals developed by the seed companies and other breeders. Multiple year results are here

The 2014 results aren’t up yet but trial results from results from 2011-2013 are available. These are large files and will take time to load, so be patient; there is nothing wrong with your computer. There is also a power point presentation of Proven Winners a brand that is often found in our local stores.
How can you best use these trial results? First of all they run the most common annuals. You will find multiple varieties of geraniums, salvia, ageratum, petunias, portulaca and other annuals that are popular for plantings. They test, in many cases, the entire series. Many breeders will turn out an entire series of plants, like the Wave petunias, with similar genetics but in different colors. Some of those colors will flower better than others and some will be better growers. This allows the gardener to make an intelligent choice as to whether he wants to sacrifice prolific flowering for a preferred color once he has narrowed his choice.

The plants are evaluated for uniformity, flowering, foliage and overall growth or landscaping value. The scale is on a 1-5 basis with 1 being unacceptable, 2 poor or below average, 3 fair or average, 4 good or nice display, and 5 excellent or outstanding. Obviously you aren’t going to get any very low ratings because growers aren’t going to submit their failures. One example, Breezy Pink Begonia got one of the lowest at an overall rating of 3.6. It started off with combined rating of 4.1 in June. By July the foliage, flowering and uniformity had dropped off with a rating of 3.6. Quality of the plant had picked up a bit in August but by September it was about done with a rating of 2.9. Breezy Pink was the best in the Breezy series. The red and salmon colors fared even worse and white was described as “Spreading plants with some poor foliage and few flowers.” These comments are also helpful; describing the plants as “compact”, “upright”, “poor foliage” and commenting on diseases or other foliage damage.

These multiple evaluations at different points in the growing season, give some insight into how the plant grows under different weather conditions and whether it has staying power. Lobelia such as Hot® Waterblue was rated highly at the beginning of the season, garnering one 5.0, but by late August most of the plants were dead with some reseeding. Magadi™ Basket White and Magadi™ Blue were better with the heat and recovered late in the season. The rest of the Magadi™ series were dead or dying by late August. Many annuals do fade as the weather gets warmer and it is useful to know if your baskets are going to be half empty as the weather gets warmer.

These tables also give the gardener some insight as to how a particular plant ranks within its species among the trial plants. There were 21 varieties of osteospermum (the groundhog’s favorite dinner) evaluated. Akila® Lavender Shades and Margarita Purple, with overall evaluations of 4.0, ranked number 1 out of the 21. This earned these two plants “Best of Species” status. There were 1240 varieties of plants evaluated and these two osteospermum with this evaluation ranked only 699. This put them in the 57 percentile, which would mean that 43% of the plants evaluated overall were better growers and more desirable plants. This might suggest that there are plants that are better growers in our area than the osteospermum. With so many duplicate scores none of the osteospermum ranked less than 10 out of 21 in their species so there were no actual “losers”. None did so badly that they were last.

Petunias were a different story. Of the 195 single petunias evaluated, Blue a Fuse from Burpee was 195 out of 195. They started deteriorating in August and were “mostly dead” by the September evaluation. Supertunia® Lavender Skies, Supertunia® Sangria Charm, Supertunia® Vista Bubblegum™, Supertunia® Vista Silverberry, Supertunia® White Improved New and Supertunia® Pink with a rating of 4.6 were all ranked number one in the single petunia class, earning best in class status and a place in the top 10% overall. There were joined in the petunia category by Surfinia® Bouquet Hot Pink Charm from Suntory, Whispers™ Star Rose from Syngenta Flowers as the number one petunias of the season. There was one new Wave Petunia this year, Wave® Purple Improved that ranked 9 among the single petunias. You would be safe this year to buy any of the over 20 varieties in Supertunia series this year, as they all ranked well above average.

The “Best of Show” award went to Desana® Lime from Suntory Flowers. This is one of the popular decorative sweet potato vines and is described as “Large vigorous plants, lime green with red margin.” It got a 4.9 rating out of 5. It shared the number one status and 4.9 rating with Illusion® Midnight Lace a burgundy vine from Proven Winners and Sweet Georgia® Light Green from Henry F. Michell – GreenFuse Botanicals another lime green with red margins. The Ipomoea got the highest ratings of any plants in the trials and there are some interesting new colors this year. One is Sweet Georgia® Heart which is listed as a burgundy cultivar that starts out green and turns a dusky red.

These trials contain 251 fascinating pages for the gardener. Check them out if you can and when you are finished with 2013 you can see if those evaluated in previous years lived up to those evaluations.