This deciduous tree is known for its cigar-like seed pods, its large leaves (6 to 12 inches), and its lovely flowers that resemble foxgloves. A mature northern catalpa can reach a height of 40 to 70 feet and a width of 20 to 40 feet. It is hardy in zones 4 to 8. The northern catalpa is pruned for the following reasons: to cut away any broken or diseased branches, to manage its place within your landscape, to provide clearance around walkways, structures, and roofs, and to remove deadwood.
Prune away dead, diseased, or damaged branches immediately, making a clean cut at the breaking point or cutting off the entire branch. Clean cuts enable the tree to heal properly and deter disease. You can do this at anytime during the year.
Make a visual inspection of your tree, and locate any branches that are infringing upon other trees or shrubs, structures, walkways and the roof of your home (if the tree is planted close to it). If you have branches rubbing on your roof, they can cause damage, which can lead to leaks in the roof.
Determine where the branch collar (on the underside of the branch where it connects to the trunk) and the branch bark ridge (on the topside of the branch where it connects to the trunk) are on the branch or limb you are going to prune. Make a clean cut in front of the branch bark ridge and the branch collar. Do not leave a stub, and be careful not to cut into the branch collar or the branch bark ridge; this should be left intact for the health of the tree. Perform this type of pruning when the tree is dormant, which is in early spring, late fall or winter.
Visually inspect the crown of the tree for dead twigs, dead branches, dead limbs and crossover branches. Removal of deadwood is called "thinning." Thinning is usually done on mature trees, and due to the heights involved, it is best that it is performed by a tree service. Not only are they used to heights and have the required tools, but certified arborists know what branches can and should be removed, insuring the health and appearance of the tree.