How to attract planners to stay planners????

Dear All

Any idea of how to retain planners to this kind of career for long time with the same employers??
As a responsible for a planning department, I want to get your ideas of:
- how we attract planners to stay planners and
- how to keep them in the company.
- even for a junior planner we want to make sure that we dont loose him after the training period is done

Any ideas??? it is a critical topic, please help out

Tarek Farid