I have a dumpy bag of conifer chippings which have been sat there for seven months. It looks the same as it did seven months ago. I am intending to use it as a mulch on a woodland, mainly rhodedendron border. Will the tannins have gone now and will it be ok to use? would it be a good idea to mix it with grass clippings to speed up the composting and reduce the anticipated uptake of nitrogen when put on the soil?