Depends on the size of the panel. Sometimes a relatively low power panel is used (5 watt) just to keep the battery charged when stored. In this case no controlling panel is needed. If it is a larger panel then a charge controller is needed.
How much power you will have for boon docking will depend on the size of he panel, the number of batteries and when electrical items you will run.
So either give us the rating of the panel or at least the physical size and we will go from there.