Hi,
I'm afraid I have never been able to find a solution to my
ferret's (Sarah) fedish for dirt.  The best I can do is keep
the plant out of reach.  The good news is, unlike cats, she
seems to have no interest in eating the actual plant and
poisoning herself.  She has, however, made a mess out of
several plants.  Also, if you move the plant for a while, your
ferret may forget about it and you can move it back.  Of
course, this is no guarentee that he won't find it again.
 
You also might try spraying Bitter Lemon/Lime on the plants.
Sarah couldn't care less, but some ferrets don't like it.
 
-Caroline (Sarah's well-trained pet)
[Posted in FML issue 1078]