This company puts styrofoam in the potting media of some of their plants. The one in particular I have experience with are the blueberry vines. I contacted the company and merely inquired as to whether the styrofoam in these plants was from shipping or if it was actually added to the media. They denied using styrofoam at all - said it was "perlite" and offered to send me a sample. I agreed and the sample of "perlite" they sent me was nothing more than flattened clumps of styrofoam beads. Perlite is non-flammable. The substance they sent me fully combusted upon being lit with a match. Don't put plants of theirs into your garden or landscaping without checking to make sure there isn't any styrofoam or you will be littering on your own property.