Fruitful training of children and roses require a goal, a plan, and diligence in labor. However, the difference is that roses have no mind of their own and only grow as they are allowed. Children are people--self-determining individuals--and they ultimately choose how they will respond to parental influence.
When my oldest son was almost 16 we let him get his first job washing dishes at a restaurant managed by a Christian friend of ours. As diehard shelterers we wrestled with whether or not our son was ready to enter the world's workforce. We knew we couldn't shelter him forever, and so finally concluded that he should be old enough to send into the world two nights a week. What we didn't realize was that he would be working with drug-using, tattooed, partiers, and our Christian friend was never scheduled to work our son's shift.