Canna lilies are not true lilies, but the flowers resembles those of the true lilies. Canna are grown in both garden beds and in pots. In areas with mild winters and little freezing, canna are left in the garden year-round. In areas with freezing winters, canna must be dug up and stored each year. Divide garden canna every two to three years after all danger of frost has passed and split stored canna just prior to transplanting them back out to the garden bed.
Brush off any excess soil on the canna tubers prior to splitting them. Locate the growing eyes on the tubers, which resemble the buds on a potato.
Break apart the tuber with the tip of the trowel into sections that have three to five eyes on each. Canna tubers have natural breaking points that are narrower then the rest of the root, so try and break them apart in these areas.
Mix one part bleach with nine parts water. Rinse each split tuber piece in this solution to kill any disease organisms present on the roots.