Looks like the white form of Obedient plant/physostegia. The site claims it isn't invasive but the pink form does spread rapidly. I yank it out every year but it comes back.

Here is a link that might be useful: Obedient plant

I'm pretty sure that it's some type of heather/Calluna vulgaris. If the flowers are quite small, it's heather. It's a lovely small evergreen shrub that thrives in sandy acid soil. One of my favorite plants, it comes in many different varieties with pink, purplish or white flowers and foliage that ranges in color from deep green to silvery to bright golds, chartreuse and even reds and oranges. An excellent plant, but not one that you can in general divide. I have had ones self-seed or had branches root that I could then separate from the mother plant, or I know that they can be started from cuttings if you are good at that, though I have never tried that. It's definitely a keeper!