Question
QUESTION: We unknowingly bought a Coral Bark Japanese Maple Acer Palmatans Sangokaku that has Verticillium Wilt from a local nursery.  We have had the tree for one month and have many trees and shrubs susceptible to the disease.  We are going to remove the tree but should we also remove all the soil around the tree root ball also?  Any suggestions would be appreciated.

ANSWER: First I hope you are sure that it is Verticillium wilt.  If this is the case, yes you should remove the tree with all associated roots and soil around the root ball.  The fungus is soilborne and can survive for many years in the absence of a host plant.  Do not plant anything back in this area.  You may even want to treat the soil area with a fumigant called Vapam of K-pam.  These sometimes can be found at garden centers.  The products are liquid and are poured on the soil. It is best if the area is covered with plastic for a few days to hold the product in place and prevent volatilization.  Everything else should be OK after that.  Good Luck.

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QUESTION: http://www.extension.umn.edu/distribution/horticulture/DG1164.html

Hi, Thank you for your quick response. I used the above site and the symptoms are as described so I am 85% sure that is what it is unless you have another idea.  I love the tree but am scared of it now. You don't have to respond unless you feel there are other possibilities.  I live just over an hours drive to a nursery for confirmation.  Thank you once again for your help.

Answer
A nursery cannot confirm the diagnosis, only a plant disease diagnostics lab can do that, because they must isolate Verticillium from the diseased tissue.  I would dig up a small root and slice into it lengthwise and look for the vascular discoloration they described in the website.  If you see this symptom, then I would think you may be right.  If you do not see the discoloration, then I might suggest that the tree is suffering from transplant shock and there is nothing to worry about, except taking care of the tree.  The dieback on one side can be from transplanting.  I would fertilize the tree and water during dry periods and forget about Vertilcillium Wilt, as it really isnt that common coming from a nursery.  You could also have the nursery check their own stock to see if any plants are affected by Verticillium and see what they say.  That may be the best thing to do initially.  I dont think they would want to be selling fungal infected trees to the public and they would let you know if there was a problem.  Good Luck.