Plants When a plant stands 9cm / 25cm, it means that the plant is in a 9 cm pot and on arrival about 25cm high. Flower bulbs If you measure 4/5 cm, it means that the bulbs are 4-5 cm in circumference. Flower bulb sizes are measured in centimeters all over the world. If it is supplied as a rhizome, tuber, tuber or a fibrous root, we call ...