It's a tree and so no I don't see how it can clash with your planting scheme. I suggest that perhaps you pleach the tree (or any multi branching tree) to emphasize the beauty of the tree amongst the backdrop of a your cottage garden bed.

Ianna

I've also been seduced by the beauty of the Lily Trees in Breck's spring catalogue and have ordered some. I plan to add them to the "mix" and look forward to seeing what they'll do in my zone 5b garden.
In your garden I think it will be a fabulous addition toward the back as it will quickly tower over the other plants ... the foliage will be a nice backdrop giving more punch to the cosmos, coneflowers and daisies.