I have a few Elms . I never heard of a Midnight Elm. Some elms do fairly well indoors , but without knowing anything your specific Elm its not possible to provide an answer. I have had success with root cuttins from a couple of Elms.
If it is a Zelkova and is a special cultivar, it may be a graft which mean that the roots could be a different species than the rest of the tree
Elms and Zelkovas are favorites trees of mine.

--
SteveW
Long Island NY

************************************************** ******************************
++++Sponsored, in part, by Mike Page++++
************************************************** ******************************
-- The IBC HOME PAGE & FAQ: http://www.internetbonsaiclub.org/ --
+++++ Questions? Help? e-mail +++++