This species is usually seen as no more than a synonym for Cana indica[]. However, since the plant can still be obtained under this name, and such plants are likely to be different, and possibly superior forms for use as a food rather than ornamental crop, the name has been retained here for the time being[].

Common Name: Achira

General Information

Canna edulis is an erect, herbaceous, perennial plant producing clumps of stems up to 3 metres tall with large leaves up to 60cm long and 18cm wide. The stems arise from a very large, thick and tuber-like rhizome[]. With its large leaves sheathing a central stem, the plant has the appearance somewhat like a small banana plant.
The plant is cultivated for its edible root in the Tropics[, ].
In tropical regions this species has sometimes escaped from cultivation and become a weed[].

Known Hazards

None known

Botanical References

, ,

Range

S. America - Argentina, northwards through S. America and C. America to Mexico; Caribbean.

Habitat

By the coast and in temperate valleys of the Andes[]. Moist or wet thickets, sometimes in rather open forest, often in secondary growth, usually at lower elevations but ascending to 2,500 metres in Guatemala[, ].

Properties

Weed Potential	Yes
Edibility Rating
Other Uses Rating
Habit	Perennial
Height	2.50 m
Pollinators	Hummingbirds
Cultivation Status	Cultivated, Wild

Cultivation Details

Canna edulis is a plant of higher elevations in the tropics, ascending to around 2,900 metres. It is very amenable to cultivation in the subtropics and can also be grown outdoors as a summer bedding plant in warmer regions of the temperate zone. It grows best in areas where annual daytime temperatures are within the range 20 - 30°c, but can tolerate 9 - 32°c[]. The top growth tolerates light frosts and plants can be grown in areas with winter snow[]. Mature top growth can be killed by temperatures of -2°c or lower, whilst fresh young growth is severely damaged at 0°c[]. It prefers a mean annual rainfall in the range 1,200 - 1,700mm, but tolerates 250 - 4,000mm[].
Requires a deep rich well-drained soil in a sunny position[, ]. Tolerates heavy soils[]. The plant has large leaves and dislikes windy conditions since this can tear the leaves to shreds[]. Requires ample water in the growing season[]. Prefers a pH in the range 5.5 - 6.5, tolerating 4.5 - 8[, ].
Plants are fast-growing, and can produce a flowering shoot in their first year of growth from seed[].
Achira is sometimes cultivated as a root crop, especially at higher elevations in S. America. There are some named varieties[, ]. The root can be harvested within 6 months from planting out, though larger yields are obtained after 8 - 10 months[]. In warm temperate climates this probably means 2 years growth is required for good yields[].
Yields in the Andes range from 13 - 85 tonnes per hectare, with 22 - 50 tonnes being average[].
The plant is possibly hardy in the mildest areas of Britain but even then it should be given a good mulch if left in the ground overwinter[]. The tubers can be harvested in late autumn after the top growth has been killed back by frost and stored over winter. They should be kept in a frost-free place covered in moist soil or leaves[].
Most cultivated forms do not produce fertile seed[]. There are also sterile triploid forms, these contain a significantly higher proportion of starch though their cropping potential is not known[].
Plants are rarely troubled by pests or diseases[].
Slugs love the young growth in spring and can cause serious damage to plants[].

Edible Uses

Root - raw or cooked[, , ]. It is the source of 'canna starch' which is used as an arrowroot[, , , ]. The arrowroot is obtained by rasping the root to a pulp, then washing and straining to get rid of the fibres[]. This starch is very digestible[]. The very young tubers can also be eaten cooked[, , , ], they are sweet but fibrous[, ]. The root can be very large, sometimes as long as a person's forearm[]. In Peru the roots are baked for up to 12 hours by which time they become a white, translucent, fibrous and somewhat mucilaginous mass with a sweetish taste[, ]. The starch is in very large grains, about three times the size of potato starch grains, and can be seen with the naked eye[, ]. This starch is easily separated from the fibre of the root[]. The roots contain about 25% starch[]. The dry matter contains about 75 - 80% starch, 6 - 14% sugar, 1 - 3% protein, it is high in potassium, low in calcium and phosphorus[].

Young shoots - cooked and eaten as a green vegetable[, ]. Quite nutritious, containing at least 10% protein[].

The immature seeds are cooked in fat tortillas[].

Medicinal

None known

Other Uses

The starch from the roots is sometimes used as a laundry starch or for sizing[].

Propagation

Seed - the different species in this genus often hybridize and so seed cannot be relied upon to breed true. If growing from seed, pre-soak for 24 hours in warm water and sow in the seeds in late winter/early spring, 2 - 5cm deep in individual pots in light shade in a greenhouse at 20°c[, ]. Scarifying the seed by carefully removing a small part of the outer shell (being careful not to harm the seed itself), to enable it to imbibe water can speed germination, especially if the seed has not swollen after being soaked[, ]. The seed usually germinates in 3 - 9 weeks[]. Grow the plants on in a greenhouse for at least their first winter. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts.
Division of the root clump as the plant comes into growth in the spring. Each portion must have at least one growing point. Pot up the divisions and grow them on in the greenhouse until they are well established and then plant them out in the summer.
Root cuttings.