I just don't know about it being a soil bactericide, or at least in sufficient strength to kill the beneficial bacteria. I only use cinnamon on plumeria and orchid "cuts" and have never had a problem when using it. Lots of folk sterilize their potting soil before use, and I have a feeling that a lot of the commercial potting soils available have been heat-sterilized as well. That would eliminate the soil bacteria as well as fungus spores. Plants grow very well in these sterilized media.