The message
from "Rupert" contains these words:

It's been stolen. I am left with a big hole and a furious temper.
It's been much admired by people who walked by along the pavement for many
years. I suppose I could replace it with a new one complete with razor
blades stuck in the trunk.

How infuriating.
I know someone who had grown an exceptionally shapely small Scots
pine tree near his gate; it looked so handsome and unusual he
photographed it. At Christmas, some scrote came in the night, sawed the
trunk and stole it. That week, the tree's picture was published in the
local paper with a message from its owner: "To the person who killed
and stole my lovely tree for Christmas; I hope you enjoy it, and that
your friends, neighbours and festive visitors all recognise this picture
and what you are".

You might try making that treefern too hot to handle.

Janet