A sachet assembly, includes a closed bag which is formed from water-permeable filter paper, and a solid substance which is contained in the bag and is at least partially water-soluble. The water-soluble solid substance comprises a preparation for cut flowers. In particular, the preparation comprises a foodstuff and/or conditioning agent and/or disinfectant and/or biocide and/or growth inhibitor. The packaging assembly includes a waterproof, or at least moisture-proof, outer packaging containing a large number of sachets. The invention also relates to the use of a sachet made from water-permeable filter paper for administering a preparation to cut flowers which are standing in water.