Organic slow release root building plant food encourages stronger roots and better plant establishment rich in phosphorus which stimulates root growth making it ideal for use when planting trees shrubs and herbaceous plants uk fertiliser declaration bone meal 3 9 0 total nitrogen n 3 total phosphorus pentoxide p2o5 9 3 9 p roi fertiliser declaration bone meal 3 3 9 0 total nitrogen n 3 phosphorus p soluble in water 0 phosphorus p soluble in mineral acids only 3 9