To maintain the compact, pyramid-shaped spiral of an Alberta spruce, prune it every few weeks. Use sharp shears that can trim branches in a single, clean cut. Begin pruning at the top of the tree and work downwards.
To shape the spiral, tie a piece of twine to a length at least twice that of the height of the tree to the top of the spruce. Wind the twine down the tree in the preferred spiral pattern. Let the size of the tree determine the size of the spirals, which should be no smaller than 12 inches wide. Clip the twine in place with clothes pins or snack clips. Prune the branches along the route of the spiral. Remove large branches in the foliage as necessary to make room for smaller branches that follow the twine spiral path naturally. Shape the smaller branches to match the spiral. Prune as needed until the spruce spirals look tidied and even.
Remove the twine and continue to prune regularly, every three weeks or so, along the shape's lines, cutting off branches that grow outside the set shape. If necessary, reshape the tree as it matures. Remove any dead, diseased or damaged branches when they are noticed to prevent the spread of disease and pest infestation by spider mites. Sterilize shears regularly to prevent spreading bacteria or mold spores from other plants.