This month we present a plant which, although found in this country, has not yet been fully appreciated in terms of the range of species available, and its value within planting schemes.  The Canna offers a range of colours and flower shapes, together with broad green, purple or variegated leaves. It will repeat flower all through the summer and bring a touch of the tropics to any garden.

The Cannas are a group of around 50 varieties belonging to the Cannaceae.  They originate from tropical regions in India, Asia, and both North and South America.  A special feature they exhibit are the tall, broad leaves which grow straight up from the ground. The flowers are also interesting in that they are asymmetrical, composed of three sepals and three petals, which are small and hidden under extravagant stamens.  The actual flowers appear within the bracts and are usually ‘doubles’.  Cannas grow from rhizomes and are extremely long-lived plants.

As this is a plant beloved of both amateur and professional gardeners, its popularity has resulted in the production of hundreds of hybrids.  Such hybrids are usually named as canna x generalis.  The original canna is known as canna indica.

lIn general canna leaves do not withstand frost, but the rhizomes can take light frosts.  In this country, in areas where only mild frosts can be expected, there is no need to lift canna bulbs in the autumn.  In regions where winters are more severe, lift the bulbs in the autumn and store in a frost-free area in a slightly moist atmosphere.

In terms of garden design, cannas are mainly used in border planting as single architectural specimens or in groups. To ensure repeat flowering, when a cluster of flowers has finished blooming cut the stem at the bottom.  The plant will then form another flower stem rather than putting its energy into spreading.