This Ox eye (Buphthalmum salicifolium) originally stood in the front yard where, except for a male Red tailed bumblebee, it atrracted no visitors. The location apparently did not provide it enough sunlight as it clearly was not happy. After repositioning to a new sunny location in the back yard she was doing well and is now well visited by especially the Ridge-saddled carpenter bee (Heriades troncorum) [1].
Here a male is drinking nectar.

Like these two males and a larger female in the middle.

Literature
1 Nederlands Soortenregister