New research indicates that, with a few exceptions, cultivars don’t have the nectar, seed, etc resources that the native plant species do. Annie White has been studying natives and nativars (aka cultivars) since 2011 in northern Vermont to evaluate their garden performance and study patterns of nectar production.
Although a couple of the open-pollinated seed cultivars were attractive to insect pollinators, it was clear “the more manipulated the cultivars became, the less attractive they became to pollinators.” White hypothesized that “color differences and decreased nectar and pollen production in hybridized cultivars are the leading factors.”
White also studied nectar production and found the volume of nectar was down in many of the nativars which means pollinators would need to visit the plants more often using valuable energy simply to maintain the same volume. She has three more research projects underway. Stay tuned for an update.
See also EcoBeneficial! Kim Eierman’s interview with Doug Tallamy for preliminary results from a research project at Mt Cuba Center, with grad student Emily Baisden, to determine if cultivars of some woody plants attract as many leaf-eating insects as native species. Results of this research should be available later this year.
Thank you Janet Allen for bringing this research to my attention.