Topiary is the art of trimming and training plants into specific shapes or designs. Some topiaries are simple cubes or spheres, and some are complex, having sections of shaped wire forms which the plants are trained to follow. A spiral topiary tree is fairly simple to create from any upright plant. Yews or other finely needled conifers are typically used for spiral trees.
Choose a tree with a straight central trunk and short lateral branches for a spiral topiary. The tree should be small enough that you can reach the top.
Tie the ribbon at the top of the tree. Wind the ribbon around the tree from the top to the bottom to mark the spiral shape you want. For best results, do not wind the ribbon too close together. Leave at least 12 to 18 inches between the rounds of ribbon. That will give the tree plenty of room to assume the spiral shape.
Prune away the branches along the ribbon's path. Trim protruding branches all the way to the trunk, if necessary.
Remove the ribbon after you have trimmed the basic spiral shape into the tree's structure. Smooth out uneven areas with small clippers.
Use small trimmers to shape the spiral as the tree grows. Clip away new leggy growth as it appears, and the spiral shape will be maintained. Allow new growth to fill in the empty areas where it is needed to complete the shape of the spiral.