Height 75-120cm (2-1/2 – 4ft)
Planting distance 45-60cm (1-½-2ft)
Flowers late summer and early autumn
Sunny sheltered position
Rhizomes available in autumn and winter
For many years it was difficult to buy the rhizomes of these tropical plants, but recently they have become more readily available. They are excellent for summer bedding with their brightly coloured blooms resembling a cross between an orchid and a gladiolus. They can reach 1.2m (4ft) high, so plant them at the back of a border. The leaves are very large, at least 45cm (1-1/2ft) long and 30cm (1ft) wide, with colours ranging from pale green, deep green and bronze to purple according to variety.
The varieties available have all been developed from C. indica but they are usually referred to as C. x hybrida or horticultural can-nas. Green-leaved varieties include: ‘Bonfire’ with orange-scarlet; ‘Denmans’ with yellow flowers; ‘Evening Star’ with dull carmine-pink flowers; ‘Humbert’s Seedling’ with scarlet flowers; ‘J B van der Schoot’ with lemon-yellow flowers speckled with purple-red; ‘Orange Perfection’, a soft orange; ‘President’, a vivid scarlet. Bronze and purple-leaved varieties include: ‘America’ has red flowers; ‘Di Bartolo’ has deep pink flowers; ‘Wyoming’ is bronze-yellow; ‘Lucifer’ has red petals with yellow edges; and ‘Verdi’ is orange blotched yellow and purple.
Plant the rhizomes 2cm (1in) deep in pots of moist compost in early spring. Place them in the greenhouse at a minimum temperature of 16°C (61°F). If more than one shoot appears on a rhizome, divide the rhizome into sections, each with a shoot and some roots, and repot. Plant out from early summer onwards in well-manured soil in a sheltered sunny position.
Alternatively, transfer young plants to tubs inand move these outside after risk of frost has passed. Bring the plants inside again before autumn frosts.
Partially dry plants lifted from beds, then cut off the leaves and roots and store them in just moist compost or leaf-mould in a frost-free place for the winter. If kept too dry, the rhizomes will shrivel and die; too wet and they rot.
In early spring, divide recently potted rhizomes which produce more than one shoot. Make sure each new division has some roots as well as a shoot. Pot them in moist compost and plant out in early summer.
Pests and diseases
Slugs, leatherjackets and cutworms eat the rhizomes.