canna 'Picasso'

Outdoors grow in a sheltered site in fertile soil in full sun, planting in early summer once frosts have passed. Water freely in dry weather and apply a high potassium fertiliser monthly. Lift the rhizomes in autumn when frost blackens the foliage. Store over winter in barely moist peat-free potting mix or leaf mould in frost-free conditions. In mild areas leave in the ground but cover with a dry mulch. Further canna cultivation advice

Deadhead to promote continued flowering. Leave to dieback in autumn

Propagate by seed at 21°C (70°F) in spring or autumn. Soak seed in warm water before sowing. Cultivars may not come true from seed. Propagate by division in early spring

Glasshouse red spider mite, slugs and caterpillars may be troublesome

Canna can be susceptible to a virus