Our tree didn't have to move on stage.  We created the tree trunk with 2 X 4s and chicken wire/papier mache, and then used real branches, stripped of all their foliage.  Attached to the tree (via holes drilled into the branches) were TONS of silk (or plastic) leaves, often available at hobby craft stores and garden centers.  They are probably much cheaper if purchased online.  The resultant tree looked very much alive and lush.  The trick was positioning the lighting among all that foliage so it wouldn't be a fire hazard.  It can be done, though.  Good luck.

I've seen great effect done with cargo netting and lighting including gobos and gelled appropriately.

I, too, have seen the cargo net used (ITW).  It looked great!

You can find the cargo netting at Army/Navy Surplus stores.  I found mine at a giant outdoor swap shop.

We also built our trees with round concrete forms 10 feet tall. We purchased large outdoor patio umbrellas and decorated them with foliage to match the backdrop we wer using. The pole from the umbrella slides down into the concrete fom. The tree became some what top heavy so make sure your base will support it.