Boxwood is a zone 4 plant and should not be expected to thrive in Alberta. I do not recommend using this plant, as growth is very slow at best, and the shrub usually looks chlorotic and sick. At my last residence, my neighbour had three boxwood plants growing between our houses. They didn’t grow at all in the 4 years that I lived there. The quack grass enjoyed growing in and around them, but that’s about it. The nicest specimens I’ve seen are in a well-manicured, protected garden in Calgary. They grow very slowly, if at all, but have formed a very small (about 1.5′ tall) formal hedge over the past 12 years. A tough winter will set them back, however, and kill areas of the hedge. Boxwood is for the adventurous prairie gardener that doesn’t mind high maintenance and digging things out and replacing them.
(c) 2014 Shane LePage, Wild Rose Garden & Tree Service, Red Deer, AB