Made To Last - A florist injects a carnation with the preserving fluid.... Florists in Germany will soon be offering to the public flowers which will last for six months. A year ago a dutch firm perfected a method of preserving flowers by injection and this method has now spread into Germany. The flowers will cost about three times as much as a normal bloom. Made to last florists in Germany will soon be offering to the public flowers which will last for six months. A year ago a Dutch firm perfe