May 20, Star magnolia (Magnolia stellata) will grow to feet tall with multiple stems in Zones It loses its leaves in the fall, and in spring the star-shape blooms appear on bare branches (plant it in front of evergreens or a dark-colored wall to really help the flowers stand out). Prune your star magnolia after it blooms to help shape it within the first five years after you Estimated Reading Time: 4 mins. When to Prune a Magnolia Tree.
For magnolias that bloom in early spring, the best time for pruning is soon after the tree has finished blooming.
This can be late spring or early summer, depending on the climatic zone. Pruning too late in the season will result in fewer blossoms the following spring.
May 25, The best time to prune a magnolia, as they don't generally like pruning, is late summer or just after the flowering has stopped. If you live where there are milder temperatures in fall, it may be suitable to do then too%.