You Can Have Your Canna and Eat it, Too
(Editor's note: This article was originally published on October 22, 2009. Your comments are welcome, but please be aware that authors of previously pubished articles may not be available to answer your questions.)
first became aware of its edibility via a DG article by Ian Maxwell, originally published in February 2008. It's the rhizome or tuber, which contains a great deal of starch, that is said to be edible, tasting much like another tuber with which we're all familiar: the potato. The most frequently eaten tubers come from two closely related canna varieties, Canna edulis and Canna indica (more about these later).
Determined to sample a canna tuber, but lacking the above two varieties, I chose Canna 'Musifolia', the "banana" Canna (see my previous article, "Out of Chaos a Mystery Plant is Born"), because its large tubers and its blossoms closely resemble those of the wild Canna edulis and Canna indica.
I decided to prepare my tubers the way the Indians of the Andes prepare them: boiled or baked. You can either boil them and eat them, bake them and eat them, or boil them first and then bake and eat them. I selected both stem buds (see photo at end of article) and mature rhizomes to see if there was a difference in taste or texture. I also sampled raw tuber so that I could compare it to the cooked and baked versions. It tasted a bit like water chestnuts, but had a slightly bitter aftertaste.
I prepared the tubers for cooking by washing the soil off thoroughly and cutting the larger ones into 1.5- to 2-inch chunks. I tried peeling some, scraping some, and leaving some as is. The exposed flesh had a slight tendency to turn brown.
Boiled results: Having read that the tubers are quite fibrous and would need to be boiled for a "long" time to soften them, I arbitrarily chose one hour on medium heat (just slightly above a simmer). When I sampled them at the end of that time, they were quite soft but not mushy. I'm guessing that half an hour would have been long enough. And how did they taste? Great! There was a hint of water chestnut, but the overall taste was very similar to new potatoes, with just a bit of sweetness. The bitter taste was completely gone. The texture was very much like that of potatoes, with no fibers present in either the mature tuber or the stem bud. I wouldn't have had to bother with peeling or scraping the chunks, as the peelings slipped right off after boiling.
Boiled and baked results: The baked tubers that were boiled first were done in two hours at 250 degrees and could probably have been baked at a higher temperature for a much shorter time. They developed a brown outer crust, much like the peeling of a potato. The white flesh inside had the texture of a baked potato and, as expected, tasted like one. Unlike potatoes however, the brown outer crust was extremely tough, almost like leather, and inedible.
Baked results: As expected, the raw tubers took longer to bake. The only instructions I could find on baking raw tubers indicated that they needed to bake at a low temperature for up to 12 hours. I baked them at 250 degrees and checked them every hour or so. After three hours they were done and were practically identical in every respect to the tubers that were boiled first.Because the tubers resemble potatoes so closely, I expect that one could mash them and flavor them a bit with garlic or celeriac. Perhaps one could even make canna chips!
There is no consensus among historians on the origin of C. indica's species name. Some believe that it originated with Linnaeus, who mistakenly thought that the plant was native to India. Others say that the name comes from "West Indies," the area from which cannas were first exported to Europe. There is no such disagreement concerning the species name for C. edulis. Edulis is the Latin word for "edible," which is certainly an appropriate description, given its use. It's known among Andean natives as "Achira." Archaeological evidence indicates that both varieties are very old food crops. Carbon dating of tubers found in ancient graves reveals that they are over 3,500 years old! The fact that C. edulis/indica was buried with the dead suggests that it was a food source of great significance.
The picture gets even more complicated than the confusion with C. edulis and C. indica and their many existing cultivars. Besides boiling and roasting them, Andean indians also dry the starchy tubers and grind them into a powder which is used as flour. The powder has come to be known as "arrowroot" (see photo of 'Queensland Arrowroot' at left above). But there is also another 'Arrowroot,' known in horticulture as Maranta arundinacea, whose roots are ground into flour as well. Then there is Zamia pumila, a cycad whose ground up roots are known in the southern states as 'Florida arrowroot.'
No matter what its source, arrowroot is almost pure starch and has many uses in the preparation of food. It's used in making biscuits, jellies, puddings, cakes, and hot sauces in some western cultures, including Australia and New Zealand. Koreans and other Asians prize it as the chief ingredient in transparent noodles. It's also frequently used in oriental cooking as a thickening for sauces, especially sweet and sour sauce. For those with gluten sensitivity, arrowroot is a useful replacement for wheat flour.
Though some of these questions still persist, I hope I've helped you navigate the interesting but somewhat confusing and cluttered terrain of the canna as a food source. If you'd like to sample Queensland Arrowroot --which despite the merging of edulis and indica into a single species is still called Canna edulis--check the column to the right for some arrowroot sources and a tasty recipe. Or, if you grow cannas in your garden, you might be tempted to sample a cooked or baked tuber as I was. Bon appetit!
Cannas are native to tropical and subtropical regions of the Western Hemisphere, from southern South Carolina west to southern Texas and all the way south to northern Argentina.
The fact that cannas are now cultivated and naturalized in most tropical and subtropical regions around the entire world is a testament to their popularity. Because their roots can be dug and stored in colder regions of the world, cannas are popular with gardeners in temperate climates as well.
In fact, some cannas are even grown above the Arctic Circle. Though the season there is short, the days are very long, which accelerates their growth. As long as they're planted after the temperature stays above freezing and are exposed to at least six hours of sunlight per day, cannas will grow and bloom before frost forces them back into dormancy and storage for the winter.
Cannas perform best in moist, well-drained soils in full sun. Water once a week during dry weather. To promote growth, fertilize once or twice during the growing season with a balanced garden fertilizer such as 10-10-10. Remove spent flowers to promote additional blooming. While cannas have a few insect and disease pests, none are considered serious. Cannas are usually grown from rhizomes that are started indoors in large pots in March or planted directly outdoors after the danger of frost is past (mid-May in central Iowa). Rhizomes should be planted 4 to 5 inches deep.
In Iowa, cannas are tender perennials. Cut plants back to 4 to 6 inches above ground a few days after a hard, killing frost. Then carefully dig up the canna clumps with a spade or fork. Leave a small amount of soil around the rhizomes. Allow them to dry for several hours. Store in large boxes, wire crates or mesh bags in a cool (40 to 50°F), dry location. Large clumps can be divided in the spring before planting. Each section should have at least 3 to 5 buds.
Antique Cannas Popular
2-1/2 cups arrowroot flour
Place the arrowroot flour on a paper towel, put it in microwave-safe bowl, and microwave for 1-2 minutes. Set aside and let it cool. Tip: You may need to microwave extra arrowroot flour later, if the dough is too wet to knead.
Sieve the arrowroot flour and sugar into a big bowl. Add the melted butter, egg yolk and coconut milk. Knead until the dough is pliable. Tip: If the dough is too dry, add more coconut milk.
Roll out the dough on a lightly floured surface to a thickness of your liking, preferably about 1/4-inch, and cut into shapes with a cookie cutter.
Arrange on a lined baking tray. Bake at 350°F for 15 minutes.
Arrowroot Flour Sources
© Larry Rettig 2009