Experts and BHG readers answer.
Tall skinny plant needed for boundary!
Thanks for writing. In your area, you have several great choices, including a variety of columnar junipers (such as 'Blue Arrow') and hollies (such as 'Sky Pencil') that will stay between 2 and 3 feet wide at maturity. Ask for columnar varieties at your local garden center.
---Justin, Senior Garden Editor, BHG.com