I have 3x 50 year old oak trees that have some low hanging branches and one heavier branch hangs over my garage. Couple of questions. Besides getting rid of low hanging and dead branches, what is needed in a typical pruning/tree trimming? Also how often should the trees be trimmed? We’ve been in the house 20 years and these are really healthy trees and we have done nothing to them in the past

Hi Eric:

Pruning is implemented for a variety of reasons, the most common of which is removal of low(er) branches to provide more horizontal space or to encourage more sunlight penetration to the ground/turf (lifting); creating crown/branch symmetry (shaping); removal of diseased or infested branches for tree health reasons; removal of deadwood for liability and aesthetics; and removal of high-probably failure or weak branch unions (poor crotch angles); and finally clearance pruning for utility operations and maintenance.

A general rule with pruning is not to remove more than 20% of the tree’s live limbs during any single pruning operation (annually) and to maintain at least 50% live canopy on your shade trees.

Excellent Pruning Resource: https://extension.purdue.edu/extmedia/fnr/fnr-506-w.pdf