I don't know the percentage exactly. I just put sufficient into my water containers to stop them from freezing. I'm trying not to overdo it because its really still an experimental procedure. There might be a concentration which could harm some trees. This is the first winter when I have been brave enough to use it on everything. I started with stuff that I could afford to lose three seasons ago and included some of both evergreens and deciduous varieties last year.
My six water containers hold well over fifty gallons and I have only treated two of them to glycerine. The others are well and truly frozen. I noticed that two containers in the goatyard which had some organic refuse in them were liquid for long after the clear water was frozen. That may have some significance for future experiment.
My name is Don and I'm a bonsaiholic. スタイミー My imaginary friend Givitago takes over when I'm not sure of myself in print. He's not a complete fool - several bits are missing. This message has been created using 100% recycled electrons