Q.Magnolia trees
I have a two year old magnolia tree. Is it necessary to prune or deadhead old blooms?
Pruning isn't an absolute necessity on Magnolia trees unless you want to shape it as it's growing. Once the tree matures, pruning is not recommended as older Magnolias don't tolerate pruning very well. Deadheading the old blooms could be slightly overwhelming due to the large number of blooms on most trees, so it's not necessary unless it's part of your pruning.
These articles may help you:
https://www.gardeningknowhow.com/ornamental/trees/magnolia/magnolia-tree-care.htm
and
https://www.gardeningknowhow.com/ornamental/trees/magnolia/pruning-magnolia-trees.htm