What a cute little Arborvitae! This selection from the Emerald Green cultivar is slower growing, thus a much smaller plant. If you are wanting a tidy, low and compact evergreen hedge, 'Little Simon' would be a great choice. It is super hardy so will live in zone 3, with winter temps down to -35 deg F. Useful as an alternate choice for boxwood, and can be pruned to make a formal looking hedge. In winter it will take on some bronze color.
