Fothergilla major or Fothergilla gardenii (depending on who you ask!)

The difference would be in the mature size. Fothergilla major can get quite large - 10-12' tall and almost as wide. Fothergilla gardenii stays about half that size. Either are great shrubs with multiseason attraction.

the smaller version can get 6 ft wide. Yes, planted way too close.

The kind of shrub that looks at home out in the open, growing in a carpet of low, evergreen shrubs (heathers in the right climate and soils).

Thank you all for your answers.

It doesn't grow too much. For the last 5 years, it has been at this size. Maybe because it doesn't get much sun and we live in a very cold climate.

Thanks again!

"It doesn't grow too much. For the last 5 years, it has been at this size. Maybe because it doesn't get much sun and we live in a very cold climate."

I see 8-12" growth for this year alone. It is growing fairly quickly so your claim must be a result of winter kill, pruning, or animal damage?