Mylar is best off ordered from internet if you don't have a hydro store near you. I've heard nothing about parathin heaters before this thread.

I completely agree with justaseed with the replanting and burying the stem.

Although, I have to disagree with the using of the dull side of aluminum in your case because it would be way more work to take everything off and put it back on than to take it off and just paint. White paint would give you much better reflectivity than aluminum foil anyway.

Goodluck <3