Pruning poplar trees is a way to direct their growth and improve their structure as they grow. Good pruning never changes the shape of the tree.
Late summer, autumn best
Prune poplar trees late in the summer or early in the autumn. Because of the oncoming cold weather, this will minimize small shoots that develop on the tree trunk from regrowing on the main stem.
Your pruning cut should expose the least amount of surface area. To begin, make a cut on the bottom of the branch. Your second cut should be on top of the branch. That should remove most of the branch. The third cut should trim the remaining part of the branch closest to the tree. Use this method to ensure that the bark does not tear as the branch falls away, which can cause a bigger injury to the trunk.
Poplar trees generally need little pruning because of their rapid and strong growth structure.
Some pruning may be necessary
However, pruning also helps to remove broken branches or to get street and sidewalk clearance. Careful pruning can protect a tree from branches breaking or becoming too crowded as the tree grows.
Check local codes
In many cities, street tree branches must provide 8 feet of clearance over a sidewalk and 14 feet above a street