This morning Prairie Moon Nursery posted on their Facebook page about a freak white Echinacea pallida in their fields. I'm quoting just the last paragraph:
"It is possible to isolate these flowers and cultivate them to be "true to seed" meaning a seed from a white flower will also be white. However, this cultivation requires artificial selection, and reduces the genetic diversity of the plant population. Since genetic diversity is crucial to a population's survival, we choose to not cultivate these genetic anomalies by breeding out this novel trait, but instead, we just enjoy this curious wonder of the natural world."
So there's another issue right there -- genetic diversity. A lot of plants in the nursery trade are produced from cuttings. What this means is a person in Atlanta could be buying the same exact coneflower as a person in Detroit. Growers, sellers, and buyers demand uniformity so the product is guaranteed to be how it's described on the plant tag. And depending on the origin of that plant, it may bloom earlier or later than when local wildlife have evolved to use it. Plus, it might not do as well in a vastly different climate. When you hear of plants being trialed it's often in one region, or if we're lucky, a few different ones. But the U.S. is a very diverse place, and even if the climate zone is the same, the ecoregion is not.
Right now about the best any consumer can do is getting a straight species plant from a similar latitude. Out here in eastern Nebraska we share a lot of the same native plants as folks in Wisconsin, Ohio, New York, and Tennessee, so getting a plant that was grown and sourced in Ohio means it might do ok out here. Or, it might not, given our drier summers. Ideally, we'd get plants of genetic origin within 30 miles, others would say 100 or 200. And if you get one from a state north or south it will bloom at a different time than the same local plants.
Regardless, the horticulture industry has a lot of challenges to face when promoting pollinator-friendly plants. We don't know what we're doing when we alter plants, but keep making new plants anyway, seemingly disregarding the quality of nectar and pollen as well as co-evolution with fauna.