Question
I have many agapanthus plants in my beds that have their leaves turning a tan color.  While they were blooming the leaves were a beautiful lush green.  Is this a natural process for these plants?  How much should I water them and how often should they be fertilized.

Answer
Agapanthus is not a hardy plant where I live so I have only grown them in containers.  The yellowing of the leaves most likely is due to lack of water.  The bulbs store water so a weekly, generous watering should suffice (the equivalent of an inch of rain or more).  A balanced, all-purpose fertilizer should be given in the spring to promote heavier bloom.  I use a slow-release fertilizer (Osmocote is one brand) mixed in with the potting soil or, in your case, the garden soil, to take care of the entire season's feeding all at once.  As most bulbs, they do require a well-drained situation.