This is a good point. I used blood, fish and bm in the past when planting shrubs and hedges, but stopped with the BSE scare we had here in the UK a few years back, when there were various warnings about using it, if I remember correctly. I don't know if there are strict regulations about the production of b,f,& bm nowadays - but I am nervous about using it now - inhalation of the dust etc. It's probably daft - I ate more beef during the scare to support the farmers than ever before - but selected with caution!