The increase of ion leakage (I.L.) of Gerbera petal cells during ageing was hastened by lowering the pressure potential of excised petals. Increasing pressure potential by placing flower stems in KNO3-solutions delayed the increase of I.L. It is suggested that differences in time curves of I.L. for cut and intact flowers are initiated by differences in pressure potential. The theory that determinations of pressure potential, water content per dry weight and dry weight per area of petals will give a good indication of potential keeping-quality is discussed.