I saw a post elsewhere about these bags, and/or fabric which apparently "protects your plants from invasive tree roots...The SpinOut coating stops roots on contact and the geotextile allows air and water permeability." Sounds great and I have a couple of sites under a maple and a pine tree where the soil is a felted mass and the existing perennials are showing signs of declining. I'm wondering if chopping out a hole and lining it with one of these bags and replanting them might give them a chance of thriving instead of just surviving. Has anyone ever used this stuff? Does it work? Is the coating toxic for the tree or surrounding plants? Are they available in BC, or by mail order in Canada?