Choose the Right Tool
Always use clean, sharp tools. Select the right-size tool for the branch you will prune to avoid damage to the plant and the tool. Use a pruning saw on branches larger than 4 – 6cm in diameter. Pruners work best on the smallest branches. Use loppers on branches an inch or so in diameter.
Choose the Right Time
There isn’t a single best time for pruning. Late winter is an ideal time for pruning many trees and shrubs because they are dormant and it is easier to see what needs to be pruned. Late-winter pruning promotes fast regrowth in spring. Some trees, such as maples, birches, and magnolias, bleed sap heavily if pruned in late winter. This causes little harm but can be avoided by pruning these trees after they are fully leafed out in late spring or early summer. Summer is the best time to remove dead branches when they stand out.
Prune spring-flowering trees and shrubs right after they finish flowering in spring. Trees and shrubs that bloom during summer and into fall are best pruned in later winter or early spring as soon as their annual growth begins. Refrain from fall pruning because it stimulates new growth that could be killed by winter cold. Prune anytime: suckers; water sprouts; branches that are dead, diseased, or damaged.
Make the Right Cuts
Holding the thinner, upper cutting blade nearer to the trunk or main stem, make a clean cut without tearing the bark. Avoid leaving a stub, which is unsightly and provides an entry point for pests and diseases. Cut just outside the branch collar, the swelling where the branch begins.