Pruning away large portions of any trees can have a stunting effect - although if major alterations are to be made when the tree is young is the time to do it.
Otherwise as with most garden trees actually established dogwoods are mostly hands off; with these trees in particular shortening branches is often not feasible because due to how they. Jun 27, Every year, in late winter, you'll want to remove about a third of the old, most faded stems from your Dogwood shrub, cutting them back to the ground. Also cut out any damaged or dead stems.
This method will encourage more new, brightly colored stems to emerge when the plant emerges from dormancy in spring. If you can keep up a consistent pruning schedule then a great way to keep you dogwood shrubs in bright colors is to just prune the oldest stems once a year in the late winter.
Just removing of the oldest stems each year on a normal size plant will accomplish the goal. Jul 06, pastime Waterman, IL (Zone 5a) Jun 24, Kousa's are very slow growing trees. Your neighbors tree has probably been around for a while. My tree is 15 years old, so I have trimmed some of the lower branches to get access to my hostas and hydrangas planted under and behind it.