A mature magnolia tree.
Some varieties of magnolia trees can reach 25 feet tall. How you cut and shape a magnolia tree will dictate whether it will grow to be the size of a large tree or a shrub. Begin pruning your magnolia tree when it is young, then, by the time it is a mature shade tree, you will only need to make a few cuts each year to help it keep its shape. Does this Spark an idea?
1. Prune your tree when you plant it.
Prune a magnolia tree when you plant it. Clip back new vertical shoots 1/8 inch from the trunk with pruning shears. Clip limbs with very narrow crotch angles 1/8 inch from the branch. Clip any diseased and damaged branches 1/8 inch from the trunk. Select and allow scaffold limbs to grow into a thick main structure for the tree and, using loppers, remove the excess branches that will not become scaffold limbs.
2. Cut vertical branches in the spring.
Prune the tree each year in the spring, after the flowers bloom. Cut branches that have grown taller than the others with the loppers. Cut one third to one half of the vertical branches back 1/8 inch from the trunk of the tree. Bend back the other vertical branches to weaken their growth and stop them from spoiling the shape of the tree. Clip diseased and damaged branches with pruning shears.
3. A mature magnolia trees should be pruned very little.
Prune mature magnolia trees very little, as they reach 20 years or older and their growth rate slows. Prune only the tallest branches or the ones with a limb spread that is wider than the rest of the branches. Cut these branches back to 1/8 inch from the trunk with your loppers. Clip back diseased and damaged branches with pruning shears or loppers, again, 1/8 inch from the trunk.