I also tried with a Tibouchina and it worked.
Sorry no pics just links to pics (I am at work and pics are stored at home...but links work!)
This is the plant, as you can see it didn't look that "nice"
http://home-and-garden.webshot...
I peeled off the "bark" a bit around the stem
http://home-and-garden.webshot...
I used a transparent plastic cup (BLACK is better???)
http://home-and-garden.webshot...
Filled it up with sphagnum (spelling?) and used tape to secure the cup around the stem
http://home-and-garden.webshot...
This is the result!
http://home-and-garden.webshot...
