Pine trees are evergreen plants, which means that every branch should feature the telltale cones and needles any time of the year, even in the depths of winter. If you spy branches on your pine tree that feature no foliage, the branches are dead. If you only see dead branches on the lower part of the tree, this is related to the regular life cycle of the tree. The important thing is to remove the dead branches before they can cause more harm to the rest of the tree.
Why Dead Branches Are Harmful
Having dead branches on your pine tree has the potential to cause more damage than simply looking bad. Dead wood on the tree will not simply fall off, the way dead leaves on deciduous trees do. Instead, the dead branches will remain, and the tree will devote water and nutrients to trying to revive them. This subtracts from the water and nutrients the tree can put into new and healthy growth, potentially stunting the growth of the tree. The rotting wood can also attract insects that feed on dead wood, and these insects can cause extensive damage that may kill the whole tree.
When to Remove Dead Branches
Removing the branches is necessary, but you must do so in the dormant season, in the winter or very early spring. In most areas, any time between December and early spring is the best time to remove the dead branches. Cutting into the wood releases sap, much how cutting human skin releases blood. The pheromones in the sap can attract insects, which will arrive and feed on the wound, potentially infesting the entire tree and causing serious damage. If you make the cuts in the winter when there are no insects about, you give the tree a chance to heal itself before the insects can take advantage of its temporarily weakened state.
Where to Cut
Cutting in the proper place on the branch will reduce the number of wounds you have to make, decreasing the chance of insect problems or heavy sap bleeding from the tree. Make your pruning cut to remove the dead branch within 2 inches of the branch collar, which is the thick area where the branch meets the trunk. You must remove this far back to give you the best control of the dead branch. If you cut in multiple pieces along the length of the branch, you risk the weight of the branch snapping the limb in the middle unexpectedly, which can cause you to go off balance or drop the pieces. Cutting this close to the boot also ensures that you remove any diseases or problems the branch might have had, just in case it was an outside cause that killed the branch.
How to Cut
Branches thinner than 1 inch in diameter can simply be cut through with one slice with sharp pruning shears. For larger branches, use a three-cut system. Make the first cut approximately 18 inches from the trunk, about halfway through the branch from the bottom. Move out 1 inch from the first cut and make the second cut halfway through the branch from the top; this will snap the branch off safely. The third cut should be 1 to 2 inches up from the branch collar, cutting down through the remaining piece of the branch. For a very thick branch, you can work alternatively through the top and bottom to avoid tearing into the branch collar with your shears.
- University of Georgia Cooperative Extension; Dead Pine Trees in Your Backyard; Paul J. Pugliese; Jan. 2009
- University of Minnesota Cooperative Extension; Pruning Trees and Shrubs; Mike Zins, et al.; 2009
- Virginia Cooperative Extension; A Guide to Successful Pruning, Pruning Evergreen Trees; Susan C. French; May 2009