Singleleaf pinyon, or pinaceae pinus monophylla, is also commonly called bristlecone pine. It is an aromatic pine tree that has short, stiff needles and gnarled branches. The species is slow-growing and spreads along dry, low mountain slopes. Pruning singleleaf pinyons when they are young helps produces a strong structure. As they mature, the purpose of pruning is to maintain the tree's structure, health, form and appearance.
Decide what shape to prune the singleleaf pinyon. The natural form is pyramidal which means it has a central strong stem with lateral branches that grow out from it horizontally. If you try to make the tree into an unnatural form, you'll have to do continual maintenance.
Use a hand pruner to cut small, thin branches. Lopping shears or small pruning saws can be used for slightly larger branches with bigger cutting surfaces and greater leverage. If you're dealing with even larger branches, about 6 inches in thickness, use a pruning saw. Chain saws will work on those thicker than 8 inches.
Identify the node, which is where one twig or branch meets another. Each spring, growth will start with buds and twigs grow until there is a new node.
Cut at the nodes in order to thin the crown. This will increase the amount of light and air that gets to the tree. Remove the branches with narrow, V-shaped connections because they are weaker and are likely already cracked. Keep all branches that are attached with strong U-shaped joints.
Achieve crown raising by removing some of the branches that are at the bottom of the tree. This will make space between the Singleleaf pinyon and the ground, and the tree will have a neater appearance.