How to Prune Oak Trees in Minnesota
- 1). Sterilize your pruning tools with rubbing alcohol. Sterilize the tools both before and after you prune your oak trees to prevent the spread of disease.
- 2). Use pruning shears to cut branches up to ¾ inch in diameter. Choose lopping shears for 1 ½ inch branches. Use a razor tooth pruning saw to prune branches that are 4 inches in diameter or smaller. Use a chainsaw for any branch over 4 inches in diameter.
- 3). Remove all dead, damaged, or diseased branches first. Cut them after the branch collar swelling. The branch collar swelling is the bump on the main trunk or on the attached branch where the new branch is attached. Always leave the branch collar swelling on the tree, and about ¼ inch of the branch.
- 4). Remove all thin and crossing branches on young trees. Remove all suckers growing at the bottom of the tree. Eliminate closely-spaced branches and branches with narrow crotches. Narrow crotches are two or more branches that are growing out of a branch or trunk that are very close together and create a small angle, more like a “v” than a “u.”
- 5). Thin the crown on your young oak tree. Thin the inside of the tree to improve airflow and sunlight penetration.
- 6). Remove low branches on mature trees. Removing lower branches ensures proper clearance under the tree for personal property and people. It also makes streets safer, because you remove any branches that obstruct corners or signs.
- 7). Remove large branches using up to 4 cuts. Cut 1/3 to halfway through the branch 18 inches away from the trunk on the bottom of the branch. Cut the top of the branch ½ inch further, and keep cutting until the branch breaks. Locate the branch collar, and cut the branch outside the branch collar and leave no stubs from the branch. Cut under the branch first, and then saw through the top, severing the branch completely and keeping the bark intact.
- 8). Keep the height as long as it does not affect any personal property or power lines. You can remove top branches by using a crown reduction method where you remove the branches above the highest lateral branches just below the power lines or other obstruction. Prune all vertical branches above and on these lateral branches at natural pruning points. Only prune height if it is absolutely necessary.
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