All the plants decide to 'play together' nicely, as evidenced by this lovely photo.

It is a thrill to find that accidentally, plants one has chosen to look well together when in bloom at the same time, also are good mates with Fall colour.
Here is a photo taken in June, with the unidentified Siberian Iris (a very tall one), from the other side, with the Filipendula vulgaris now behind, and not quite yet in bloom.