Caring for and maintaining Dahlia tubers
In well drained soil and in areas with mild (>CZ8) to no frosts, dahlia tubers can be left in the ground for many years and only lifted and split every 3-5 years to renew vigour. However, in moist clay soils and or in climates that get heavy frosts (<CZ8), tubers should be lifted and stored during winter months.
...
