What to plant with whipcord arborvitae, front foundation, north west corner, shade part sun?
Of course, people would need to see it in order to have a suggestion.
I think that heuchra would look good. The texture and size of the leaves would be an interesting contrast.
There are many to choose from. We could give better help, as Yardvaak suggested, if you posted a photo.
And they could appreciate a little shade.
Although the Wipcord would do best in sun.
Here is a link that might be useful: Heuchera in Your Garden