How to Grow Cannas

Exotic Plants for Temperate Climates

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Cannas are a rhizomatous tender perennial with attractive green, bronze, bronzy orange, rich scarlet, purple or striped foliage that come as dwarf, medium and tall plants. Cannas come in a wide range flower colours from pale cream, lemon, apricot-pink, white and gold to vivid yellow, orange, red, scarlet and deep crimson. The flowers may be fringed, striped or self-coloured.

In subtropical or warm temperate areas cannas will flower for most of the year. The tall forms make good subjects for the larger tropical garden or by the pool and are often grown for their leaf colour. "Tropicana" for example has deep crimson leaves striped in deep green to black that often appear luminescent when caught by the light. "Bengal Tiger" with it's green and yellow striped leaves is another cannas commonly used to give a jungle look and feel to the garden.

Cannas x generalize is the name given to the many cannas x hybrid cultivars available that are often grown in tropical beds or along a driveway where they are grouped into one colour. In the general garden cannas can be skilfully blended into a border or used as a foliage backdrop plant. Look for cultivars with golden striped foliage to add colour contrast for borders or bedding schemes. Cannas do well in tubs or large containers where they look good with low growing foliage plants.

Although cannas are hardy they do best in areas with consistently warm summers. They grow well in semi-shade but produce the best blooms when grown in full sun.

Plants can be obtained from a local nursery, grown from seed or from root division (do you have a friend with a few plants to spare?). Plant in a rich humus soil about 45-60 cm (18-24 inches) apart in a garden bed that has been well dug over and fertilised.

After the first year's flowering cut back all the stems to ground level and give the soil a good topdressing of well decayed animal manure (if you can get it) otherwise use well-prepared compost. As soon as the growth resumes again give a side dressing of balanced fertiliser.

Cannas can quickly become overcrowded with the soil may no longer able to support them. This can cause the flowers and stems to grow progressively smaller. To maintain vigorously growing plants with strong stems and large flowers remove stalks that have finished flowering by snapping off at the base with a sharp tug at ground level. Divide clumps in spring every second year. Discard old rhizome root stock and replant only those with strong young shoots.

Sometimes variegated Cannas such as "Bengal Tiger" will start to loose their gold stripes and revert back to plain green leaves. This can be caused by a number of factors including lack of light, too much nitrogenous fertilizer or a reversal of the original genetic mutation that created the stripes in the first place.

Cannas like moist soil so keep well watered during dry weather conditions. Keep an eye out for slugs, snails and earwigs who enjoy dining on the leaves and flowers.

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