Mt. Cuba Center’s latest research report on coreopsis details the results of a three-year study on the attractive garden plant. Because of the recent surge in popularity of coreopsis – and mixed results in the vitality of some selections within the genus – plant experts at Mt. Cuba Center observed the growth habits, vitality and ecological value of 94 different selections of perennial and annual coreopsis. The newly published Coreopsis Research Report ranks the top performing cultivars for the Mid-Atlantic Region.

“We want home gardeners to feel comfortable buying these plants and to know which coreopsis are most likely to succeed in their gardens,” said George Coombs, the Research Horticulturist at Mt. Cuba Center who led the study.

Researchers studied the habitat, floral display, disease resistance and longevity of each selection. They found that while many of the most popular cultivars currently available at garden stores performed poorly, several overlooked species were recognized because of their outstanding performance.

As home gardeners become more aware of the role their landscapes play in promoting healthy ecosystems, demand for native plants that provide ecological benefits as well as beauty in the home garden has increased. Coreopsis, commonly called tickseed, provides great ecological value to pollinators with its multitudes of flowers that bloom from early spring to fall, depending on the cultivar.

To more closely examine the relationship between pollinator and plant, Mt. Cuba Center partnered with the University of Delaware to use the coreopsis trial to study pollinator activity on coreopsis flowers. The research is ongoing, but preliminary results suggest that certain pollinator communities have strong preferences for specific cultivars.

“So far, the preference seems independent of color,” said Coombs. “I think the key takeaway we have so far is that planting a diversity of flower types is going to benefit the widest range of pollinators.”

“We want more than a pretty flower,” said Eileen Boyle, Mt. Cuba Center’s Director of Education and Research. “Our graduate fellows are studying the ecological value of native cultivars because we want plants that will support wildlife and perform important environmental functions. In the Coreopsis Research Report, we looked at different coreopsis and their pollinator communities. In the future, we will publish studies that include valuable information on pollen nutrition in coreopsis, nectar content in phlox and monarda flowers, and nitrogen fixation in baptisia. We are even planning for citizen scientists to participate in data collection to enhance our understanding of the ecological value of native plants.”