The spring-blooming flowering dogwood (Cornus florida) naturally attains a spreading, tiered branch form that rarely needs pruning to look pleasant and remain healthy. Choose well-structured and healthy plants at the nursery before planting so less pruning maintenance is warranted in future.
Structural pruning is best undertaken in very late winter or early spring before flowers or leaves appear. Examples of tasks include removing extremely low branches that are hazardous, rub against other branches or are malformed.
The U.S. National Arboretum warns that flowering dogwood bark is thin and easily injured. Bernheim Arboretum and Research Forest mentions this tree does not tolerate heavy pruning well and the wounds heal very slowly. These wounds may rot and also provide a means of entrance for boring insects.
Dead branches or diseased parts of the flowering dogwood warrant removal as soon as they are seen. Prune them away any time of year, making the pruning cut at the lower point of attachment to the main branch or tree trunk.