During the summer of 2006, doctoral graduate student William Smith exposed Buddleia davidii seeds to ethylmethane sulfonate (EMS) in the hope of generating some novel traits in butterfly bush. EMS is a chemical that can be used to induce a higher rate of mutations in plants. When the treated seeds were grown in 2007, two were identified that Brand believed were important new plants.

The first plant was a variegated individual whose leaves had a yellow edge around a dark green center. Variegated plants are always popular because the foliage adds interest even when the plant is not in bloom, according to Brand. The foliage variegation pattern was very stable, which is not always the case with variegated plants, and light blue flowers were also produced during the summer. Spring Meadow Nursery in Michigan, a commercial grower, decided to license the new butterfly bush and include it in their Proven Winners® product line as “Summer Skies.” The plant was patented (USPP 22465) and also holds Canadian Plant Breeder Rights.

“Fortunately, 50 percent of the seedlings from the compact mutant plant retained the dwarf characteristic,” Brand notes. “We then selected out the plants with the best flower colors in each color group from hundreds of seedlings.” By 2010, Brand knew he had something special. He continued reproduction of the new plants using softwood stem cuttings, and since that time each plant has retained its unique features in successive generations. He filed for four patents in June of 2015.The second unique seedling was picked from the hundreds initially grown out from the EMS treatment was one with a unique growth form, low growing and compact, bearing thick stems, large leaves and a frosted appearance to the foliage. But the color of the flowers was lackluster. Brand wanted to retain the compact habit of the new seedling, but breed it to produce flowers that had stronger, more vivid colors. To do this, the compact butterfly bush was crossed with four standard-sized butterfly bushes that have vibrant flower colors.

“These new Buddleia are dramatically different in their appearance than anything else on the market,” Brand says.Brand sent the plants to Spring Meadow Nursery. The new butterfly bushes were first offered in 2016 exclusively at Walmart, as the Soda Pop series within the Better Homes and Garden line.

Unlike other dwarf plants, the UConn Soda Pop series have big leaves, big chunky stems and full-sized flowers on a plant that stays between three and four feet tall, even when left unpruned, says Brand. “That’s what makes them unique.”

The response to the new line was so positive that Spring Meadow bred the new cultivars with some deeper color plants to expand the line. These plants are part of their Proven Winners® line, under the Buddleia Pugster™ Series. “Our material was so impressive it led to an additional line of Buddleia touted as a major breakthrough in butterfly bushes,” Brand points out. “I expect there will be more future butterfly bush introductions that will trace their genetic roots back to the compact mutant that was produced in our breeding program.”

Royalty monies from plant cultivars help to fund continued research by students. So far, the royalty income has gone toward lab supplies and other necessities such as plant media, containers and fertilizer.

“I think the bulk of our royalty funding is yet to come,” Brand says. “We have quite a few cultivars out there including an ornamental switchgrass, several varieties of butterfly bush and some chokeberry. We also have a number of plants in trials with commercial growers and some, such as a compact form of purple-leaf sand cherry, and sterile barberries, are licensed and in the production pipeline.”Royalty monies from plant cultivars help to fund continued research by students. So far, the royalty income has gone toward lab supplies and other necessities such as plant media, containers and fertilizer.

This story was originally published in Naturally@UConn, a blog by the College of Agriculture, Health and Natural Resources.