Considered a boreal, Northeastern type of plant, a typical speckled alder will reach upwards of 10 to 15 feet in height. If growing conditions are ideal, with very moist and rich soil, and pruning is done correctly your speckled alder could grow into a 30-foot tree. The key to proper speckled alder pruning is planning before you prune to ensure you do not remove an excessive amount of branches.
Prune trees in their dormant stage during the winter months.
Mark the branches that are to be pruned on the tree with brightly colored chalk. Planning which branches to cut beforehand will help to ensure you do not over or under prune your tree.
Prune all dead branches. When planning which branches to prune, be sure to include all the dead branches. Removing these will help healthier branches get the nourishment they need.
Begin at the trunks. If your speckled alder has multiple trunks, remove all but one.
Prune the lower branches. You are aiming for a tree shape. All of the lower branches should be removed, leaving the one tree trunk.
Thin the crown. Ideally, to create a true tree form out of your speckled alder, prune all but three main trunks in the crown area.