This popular ornamental plant can be seen blooming everywhere in midsummer, but it is also a valuable part of a survival garden. The leaves and flowers are showy and tropical, shooting up from a rhizome that is loaded with starch.
They are closely related to ginger, and will do well in any area that ginger does well in. Like ginger, they will freeze to the ground in wintertime and come back next spring. Cannas can handle full sun if planted in well-drained soil with adequate rainfall. Like taro, they do well in fairly damp areas.
The roots can be dug and cooked like a potato, usually for at least two to five hours. Traditionally the rhizome was cooked then mashed and strained to remove the fibers. The starch is well known for being easily digestible for infants and elderly. In Vietnam, large amounts of canna are grown to make cellophane noodles.
If the rhizomes can be used as a potato, it would logically follow that a very enterprising individual could distill liquor from them much as a vodka is made. Perhaps cannas and taro could be a great source for a southern alcohol bio-fuel?
The leaves and stems are used as animal feed in some areas, as cannas can grow well on marginal lands with little soil nutrition. The plants are relatively unaffected by pests, which is no surprise considering how well they do here in Florida.
Ms. Wildcraft from Backyard Food Production put up a great little video about some plants that are useful and can really take the heat. If you want to skip to the part where she talks about cannas, that would be about five minutes into the video.