I've got a spot for a 5-6–foot shrub and want to plant one of the paniculatas with green blooms...but I am struggling to decide which cultivar, since I've read that they can sometimes outgrow their expected heights (3-5 for little lime and 6-8 for limelight).

Anyone with a little lime find that they grow larger than the expected 3-5 feet? Would it be a lot of work to keep limelight at 6 feet?

I'm in zone 6b, at the edge of the Philly suburbs.

Thank you!