That sounds good. One of those Black Lace Elder shrubs would look good with them. I think some pink roses would look good with it too. Maybe the Pink Double Knockout Rose. Pink and Green look good together.

I also saw some Green and Orange combos that look awesome. Easy Does It Rose and these would look good together as well.

Good idea, I might add one as a speciman where I need more height next to the hydrangeas.

Funny you mention the Knockout as I plan to have a massing next to the hydrangeas. I mainly went knockout since the foilage is a dark purplish color...so it should pop on the mauve multi-colored brick I have.