hi , i have a felix jury magnolia that i have had for the last 10 months ,the problem is now that i have noticed that it has lost all its leaves and looks like its dieing? some of the roots at the top have appeared and look dry and dead? some parts of the main steam are going very dark also. what is the best thing to do? should i take it out the pot its in and try and look at the rest of the root sytem? and then re-pot?. any help would be greatfull as i dont wish to lose this plant. thanks.