photo: the clean summer foliage of ‘Allegheny’ viburnum Must you plant an evergreen hedge when a semi-evergreen flowering shrub is fine for the task? Leatherleaf viburnum hybrid cultivars ‘Allegheny’ and ‘Willowwood’ are 60% evergreen, dropping their foliage very late in autumn in U.S.D.A. zones 6 and 7-a. ‘Willowwood is preferred over ‘Allegheny’ in areas of […]