Although evergreen shrubs add color to the landscape and retain their foliage even during the winter months when deciduous counterparts turn barren or brown, regular pruning is essential for their upkeep, appearance and maintenance. Removing dry, damaged or diseased foliage, stems and branches invigorates the shrub, controls size and spread, and lessens the load, specially if it is old. Many different types and varieties of evergreen shrubs exist, so knowing the natural shape of the one you want to prune is essential so you prune it in accordance to its natural shape.
Cut off damaged or diseased branches with a sharp pair of pruning scissors. Walk all around the shrub to remove these from the sides, top and underneath the canopy. Scrape the bark to determine whether the cambium layer underneath is green and healthy or brown and dry. Snip the branch off if brown.
Thin the crown to reduce the load, allow sunlight to penetrate and promote good air circulation to all parts of the shrub. Cut weak, overlapping or wayward branches, and thick ones that give the shrub a dense appearance.
Snip off low-lying branches, those that touch the ground or rub against a nearby garden structure. Consistent rubbing causes wounds and makes the shrub susceptible to fungal disease. Make all cuts back to buds or the trunk.
Clip away cats' heads--a framework or tangled mass of twigs that grows from a single branch. These are formed due to frequent pruning. Prune these so secondary branches, or those that grow from the main branch, lie on each side of the trunk.
Cut branches back to healthy buds to encourage new growth. Make the cut at a 45-degree angle to encourage a new stem to develop from the bud. This technique of pruning is called "heading".
Step back and review your work. Stick to the natural shape of the evergreen shrub as much as you can, so you do not alter it. Collect all the clippings after you finish pruning in a tarp or wheelbarrow and discard.