Is it permissible for young boys to grow their hair long?

There is no harm in lengthening the hair of boys and others, as long as it is not 'qaza' (shaving part of the head and leaving part). The hair of the Prophet, peace and blessings be upon him, reached his earlobes. Whoever lengthens his hair in imitation of him will be rewarded if he maintains the appearance of the Prophet's hair, peace and blessings be upon him. Actions outside of worship can be rewarded if their doer intends them as an act of drawing closer to Allah or in imitation of the Prophet, peace and blessings be upon him. As for one who lengthens his hair arbitrarily or shortens it, there is no sin upon him, because it is among the permissible matters.