I live in Europe, and planted several non-native perennials, most notably:
For all species, I chose several cultivars, for the sake of experimenting.
Although all three species are listed as bee-attractive, bees at my place like only echinaceas and hellenuims. They totally ignore rudbeckias! Is there any plausible explanation for this?
Can it be that european bees are just not used to rudbekias, or simply don't like it, while american bees do?