I'm not sure that anyone will want a regular tutorial on the tutorials page for this, so I'll do a quick and dirty here.
I figured out a way to "move"
an object up
In doing so, I made it look as though some ferns were growing in one of the WA relics (an urn or vase).
1. I put a foundation next to where I wanted the fern raised.
2. I added flooring out over the spot where I wanted to put the fern.
3. I typed in <constrainfloorelevation false>.
4. I used single steps to lower the flooring to the level I wanted my fern.
5. I placed the ferns on the lowered temporary flooring.
6. I deleted the flooring and the foundation.
7. I placed the vase on the ground "under" the raised fern!