In Poinsettia trials at the Danish Institute of Agricultural Sciences at Aarslev and at HRI Efford in the UK, the new granular buffer ‘Compalox-P’ made from Aluminium oxide has been found to exert the same dwarfing effect as growth regulators. ‘Compalox-P’ contains a lower pre-determined and stable level of phosphorus but binds excess phosphorus in the soil. By reducing the amount of phosphorous in the soil, plants produce more roots and less vegetative growth by reducing internode length. The effect is exactly the same as is determined by the use of growth regulators, though a reduced application of growth regulators might still be necessary, on more vigorous varieties. Poinsettia growth and nutrition in pots is very complex and the composition of irrigation water needs to be examined prior to the use of ‘Compalox-P’. Pot Chrysanthemums also respond to this new product. Commercial Greenhouse Grower