Hi, Any thoughts for the best filler for big pots? I am trying to use a big pot with a nursery pot inside, and need something to fill the space between the two pots. I filled one with pine chips. Will this work or will it be too buggy? I need something fairly light weight (not rocks) that I can dump out in Fall as the nursery pots will go into the coldframe or basement. Could use peat and then use it to winter protect...

Any thoughts on a good, easy to handle, reusable material? I know some people like to use styro peanuts, but I want to avoid them, if possible.