Pawpaw, known botanically as Asimina triloba Dunal and more commonly as Indiana, Hoosier or Poor Man's Banana, is a small flowering and fruiting tree native to the eastern United States and naturalized in temperate Midwest states as well. According to Purdue University, pawpaw is the sole relative of the tropical fruit family that includes cherimoya, atamoya, guanabana and soursop, which can tolerate cool and temperate climes. The trees will mature and begin to produce harvestable fruit in five to seven years of age. Established pawpaw trees do not require pruning, but can tolerate some trimming, which will, however, diminish fruit production.
Prune away dead, diseased, cracked, abrading or otherwise compromised branches in the canopy in the late summer, early fall or in the spring. Cut back to the point of healthy wood or down to the parent branch, placing the cut just outside the slightly swollen branch collar.
Reduce the spread of the canopy by cutting the branch tips back to the desired length. Follow the natural, slightly pyramidal contours of the tree as much as possible and refrain from topping the tree which can alter the form permanently.
Work in circles around the tree to space the cuts evenly and maintain symmetry. Remove no more than one-third of the tree canopy mass to prevent stress and shock from occurring.