The Canna lily (genus Canna) is a tropical and subtropical summer-blooming plant with broad flat leaves that grow out of a stem in a long narrow roll and then unfurl. The plants grow over five feet tall but are most often around three feet tall; they often bloom red, yellow, orange, or any combination of the three in spots or variegated; the leaves are typically green but may be a deep maroon instead.
The canna may rot if left unprotected in freezing conditions, but it is a perennial plant in temperate zones; it does well with moderate water in well-drained rich or sandy soil and is largely free of pests. In areas which go below about -15°C (5°F) in the winter, the rhizomes (horizontal roots, not unlike those of a potato) can be dug up before freezing and stored in a protected area for replanting in the spring.
The flowers attract hummingbirds. The plants sometimes fall victim to Canna leaf rollers, or Brazilian skippers, the larval stage of a butterfly that cuts the leaves and rolls them over to live inside while pupating (the lesser canna leaf roller will sew the leaves shut before they can unfurl). Affected leaves can be cut off and destroyed or unrolled and cleaned (removing the caterpillar), though some gardeners prefer to use Bacillus thuringiensis, insecticidal soap, or the chemical malathion to kill the pests. In areas with a freezing winter the leaf roller is not typically a pest.
Cannas may also fall victim to canna rust, a fungus resulting in orange spots on the plant's leaves. Rust infestation is facilitated by overmoist soil.
Canna rhizomes are edible and rich in starch and were once a staple foodcrop in Peru and Ecuador. However the rhizomes can be quite fibrous and must be steamed or boiled for hours to soften for consumption. When cooked they have a taste resembling sweet potato.
Canna is grown for human consumption in the Andes and also in Vietnam and southern China, where the starch is used to make cellophane noodles.
Cannas were once very popular as a garden plant and were grown widely in France, Hungary and the United Kingdom during Victorian times. However their glory became victim to fashion change but are recently having a comeback. There were once hundreds of varieties but this dropped about 50%-70% to the current number of about 270.
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