Pine trees are a type of evergreen tree, which means they grow leaves year round. Unlike deciduous trees, they have needle-like leaves with seed-bearing cones. They generally need less pruning. Pine trees need to be trimmed only to remove dead or damaged branches or to encourage new growth. The best time of year to prune pine trees is late winter or early spring. Incorrect pruning could severely damage the development of the plant and, in some cases, even kill it.
Trimming For Corrective Reasons
Pines trees are usually trimmed for corrective reasons to remove broken or diseased branches and prevent insect invasions. The best time of year to trim a tree for corrective reasons is during the winter season, when the plant is in dormancy. This will encourage healthy growth of the tree for spring. However, if your tree has incurred unexpected damage from bad weather or other reasons, you should prune the tree immediately, no matter the time of year. When pruning a pine tree for corrective reasons, always cut back to the healthy branches, below the dead or diseased area. If you do not cut all of the old wood back, no new branches will develop.
During springtime, the chance of insect and disease invasion to your tree is less likely. Therefore, if you want to maintain the shape and size of your tree, you should prune your pine tree after the first flush of growth in spring, according to technician Susan French and horticulturist Lee Appleton of Virginia Tech University. During this time you should notice the growth of new shoots, or candles, at the tip of the branches. Cut these candles about halfway. This will help stimulate new buds and encourage density of the tree. If you want to maintain the development of your tree, repeat this process annually.
When Not to Trim
Unless your tree has had unexpected damage, avoid trimming your pine tree during the late summer or early fall. If you do prune your tree during a dry summer season, you risk the chance of bark beetles attacking your tree. According to an article on Yardener.com, bark beetles can attack a tree in such numbers that they can kill it.
Trimming during the fall can also cause serious damage. Trimming a tree during any season will normally stimulate new growth. However, new growth stimulated during the fall may not wane off before the start of winter. This could cause the pine tree to become damaged, or even killed, by the harshness of the cold weather.