Answer: Underground steam known as the rhizome
Ginger is a modified, underground stem that will spread through its stem vegetatively. There is no propagation of ginger by its root or leaf. Propagation Ginger is vegetatively propagated from small sections of the rhizome, called sets. Sets are produced by cutting a small 3–6 cm from a living rhizome. Each piece should possess at least one living bud which will produce shoots. Ginger plants require an average annual rainfall of between 250 and 300 cm for optimal growth and development and require additional irrigation where rainfall is not adequate. Ginger plants will not tolerate waterlogged soils.