5 bags of cow manure (don't substitute with chicken manure which will be too strong and burn roots) 1 cup of Blood and Bone 1 cup of Sulphate of Potash 3 cups of Dolomite
Method
This magic mulch recipe should be mixed together before being laid, 10cm deep, around the base of your trees (especially Magnolias) and shrubs. You can apply this twice a year.