But . . . I considered it:
A good wildflower for dry shady areas, so it might work spread about in the dining room window garden. It's delicate and pretty, and the tall flower spikes have some height.
I grew it in my old garden, at first in some sun around the birdbath, and later in deep shade under the maple. It did well in both places, and spread, particularly under the maple. It bloomed in late spring, but was still showing flowers in July.
It got quite tall and sometimes needed staking, but it may be less gangly in dry shade here. Possibly?
In the small dining room window garden, bounded by the house behind and by rocks in front, it might not spread about so much. Or at least it will be easier to pull up any unwanted seedlings.
This seems like a good possibility for this shady garden. Pretty, delicate white summer blooms with some height. Tolerant of shade, wants moisture but will take dry rocky soil.
The seedheads (the thimbles) after flowering remain interesting.