The Messenger of Allah (may Allah's peace and blessings be upon him) forbade Qaza‘. (qaza:shaving part of a boy's head and leaving other parts unshaven) [Al-Bukhari]
"نهى رسول الله -صلى الله عليه وسلم- عن القَزَع. [صحيح] - [متفق عليه."
