Hi, I have two mature evergreen Magnolias on my dock. They are very healthy. I want to prune them for three reasons, 1. to maintain their health, 2. to lower them in order to unobstruct my view of the lake from the upstairs of my home, and 3. to provide denser shade on the dock. I also want to trim the underside for more headroom. Is there a procedure I must follow in order to achieve these things but not harm them? Thank you very much, Chris
Pruning does not improve health, except for making the pruner feel better - when they are satisfied with the result. Magnolia grandiflora tolerates being pruned into unnatural shapes, such as espalier and large topiary. So you have some flexibility. However, I would not top yours so hard they suddenly have open, bald tops as I suppose there might be some sun damage to the branches afterward. Cannot get more specific without viewing the plants in person and finding out where you want to cut.
I second the point about pruning not being helpful in regards to tree health. Topping trees ALWAYS results in funny looking trees that are less healthy. While you can limb the magnolias up (lollipop them), it's not going to return a desirable result. Like dogwoods, these trees generally look better tiered (with limbs all the way to the ground) once you start limbing them, the above limbs will droop, necessitating further limb lopping... Hate to say it, but for health concerns, the best thing you can do is leave them be.
