A hinoki cypress tree should be trimmed when it's experiencing new growth and the danger of frost has passed. The only items needed to trim a hinoki cypress are pruning shears and disinfectant spray.
Remove damaging branches
Remove dead, damaged or diseased branches using pruning shears. Cut the branches off at the base. Disinfect the shears between each cut with disinfectant spray to prevent spreading disease to other parts of the tree. Diseased and damaged branches look wounded or scarred. Trim branches that cross each other to prevent them from causing rubbing wounds.
Cut forked branches
Locate forked branches and remove one, creating a single branch. Branches that are forked can break under ice and snow.
Remove narrow crotch branches
Cut narrow crotch branches. Narrow crotch branches are branches that don't have a good attachment angle. The wood that holds the branch to the trunk is compromised because there is excess bark built up in the angle. The branch can injure the tree by falling.
Trim tips of branches
Use pruning shears to trim the tips of the branches in the shape desired. Cut off branches that grow downward. Don't cut into the brown, aged stems because new branches will not grow back.