Tubers planted to soil depths of 80 cm produced new plants. Tubers tolerate high temperatures, but not freezing. Typically only 1 tuber in a chain germinates, unless the chain is severed. Low oxygen and high carbon dioxide levels appear to promote tuber dormancy. Tuber dormancy is high in undisturbed soils and at deeper soil levels.
Tubers can remain dormant for long periods and can become dormant after sprouting.
Tuber dormancy often increases with age. Tubers planted at a depth of 90 cm are usually unable to produce aerial shoots. Tubers desiccate quickly when detached from the rhizome-root system under dry conditions and can survive flooded soils for at least 200 days. Tuber longevity is variable and depends on environmental conditions. In most cases, tubers survive about 3-4 years, but under certain conditions they can remain viable for up to 10 years or more.