This condition may be what is called "sectioning out" where a section of a plant fails to continue to grow. This may be caused by rodent damage or perhaps disease. If feeding damage is evident, prune away the dead branch and provide winter protection in the future. if a disease is the cause, removed any cankered stems. there may be stems with cankers that are for now still alive. If the fungal disease makes its way down into the crown, the plant will struggle to survive and not perform as expected. You may have diseases in Littleton that do not present themselves here in the mid-west. Contact your local Extension Service for more local information.
